Statistics of problem solving ⭐

JAVA

BASIC

Name	Problem	Solution	Time Complexity	Space complexity
Delete Node in a Linked List	https://leetcode.com/problems/delete-node-in-a-linked-list	Delete Node in a Linked List	$O(1)$	$O(1)$

EASY

Name	Problem	Solution	Time Complexity	Space complexity
Add Binary	https://leetcode.com/problems/add-binary	Add Binary	$O(N)$	$O(N)$
Add Two Integers	https://leetcode.com/problems/add-two-integers/	Add Two Integers	$O(1)$	$O(1)$
Alternating Digit Sum	https://leetcode.com/problems/alternating-digit-sum/	Alternating Digit Sum	$not specified$	$not specified$
Ant on the Boundary	https://leetcode.com/problems/ant-on-the-boundary	Ant on the Boundary	$not specified$	$not specified$
A Number After a Double Reversal	https://leetcode.com/problems/a-number-after-a-double-reversal	A Number After a Double Reversal	$not specified$	$not specified$
Apply Operations to an Array	https://leetcode.com/problems/apply-operations-to-an-array	Apply Operations to an Array	$not specified$	$not specified$
Array Partition	https://leetcode.com/problems/array-partition	Array Partition	$O(N * LogN)$	$O(1)$
Available Captures for Rook	https://leetcode.com/problems/available-captures-for-rook/	Available Captures for Rook	$not specified$	$not specified$
Average Salary Excluding the Minimum and Maximum Salary	https://leetcode.com/problems/average-salary-excluding-the-minimum-and-maximum-salary	Average Salary Excluding the Minimum and Maximum Salary	$not specified$	$not specified$
Backspace String Compare	https://leetcode.com/problems/backspace-string-compare	Backspace String Compare	$O(N)$	$O(N)$
Baseball Game	https://leetcode.com/problems/baseball-game	Baseball Game	$not specified$	$not specified$
Best Time to Buy and Sell Stock II	https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii	Best Time to Buy and Sell Stock II	$O(N)$	$O(1)$
Binary Search	https://leetcode.com/problems/binary-search	Binary Search	$not specified$	$not specified$
Binary Tree Inorder Traversal	https://leetcode.com/problems/binary-tree-inorder-traversal	Binary Tree Inorder Traversal	$O(N)$	$O(H)$
Binary Tree Paths	https://leetcode.com/problems/binary-tree-paths	Binary Tree Paths	$O(N)$	$O(N)$
Binary Tree Postorder Traversal	https://leetcode.com/problems/binary-tree-postorder-traversal	Binary Tree Postorder Traversal	$not specified$	$not specified$
Binary Tree Preorder Traversal	https://leetcode.com/problems/binary-tree-preorder-traversal	Binary Tree Preorder Traversal	$not specified$	$not specified$
Build Array from Permutation	https://leetcode.com/problems/build-array-from-permutation/	Build Array from Permutation	$not specified$	$not specified$
Buy Two Chocolates	https://leetcode.com/problems/buy-two-chocolates	Buy Two Chocolates	$not specified$	$not specified$
Calculate Delayed Arrival Time	https://leetcode.com/problems/calculate-delayed-arrival-time	Calculate Delayed Arrival Time	$not specified$	$not specified$
Calculate Money in Leetcode Bank	https://leetcode.com/problems/calculate-money-in-leetcode-bank	Calculate Money in Leetcode Bank	$O(N)$	$O(1)$
Can Make Arithmetic Progression From Sequence	https://leetcode.com/problems/can-make-arithmetic-progression-from-sequence	Can Make Arithmetic Progression From Sequence	$O(N * LogN)$	$O(1)$
Can Place Flowers	https://leetcode.com/problems/can-place-flowers	Can Place Flowers	$not specified$	$not specified$
Cells in a Range on an Excel Sheet	https://leetcode.com/problems/cells-in-a-range-on-an-excel-sheet/description/	Cells in a Range on an Excel Sheet	$not specified$	$not specified$
Check Balanced String	https://leetcode.com/problems/check-balanced-string/description/	Check Balanced String	$O(1)$	$O(N)$
Check if All A's Appears Before All B's	https://leetcode.com/problems/check-if-all-as-appears-before-all-bs/	Check if All A's Appears Before All B's	$not specified$	$not specified$
Check if All Characters Have Equal Number of Occurrences	https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences/	Check if All Characters Have Equal Number of Occurrences	$not specified$	$not specified$
Check if a String Is an Acronym of Words	https://leetcode.com/problems/check-if-a-string-is-an-acronym-of-words	Check if a String Is an Acronym of Words	$not specified$	$not specified$
Check if Bitwise OR Has Trailing Zeros	https://leetcode.com/problems/check-if-bitwise-or-has-trailing-zeros	Check if Bitwise OR Has Trailing Zeros	$not specified$	$not specified$
Check If It Is a Straight Line	https://leetcode.com/problems/check-if-it-is-a-straight-line	Check If It Is a Straight Line	$not specified$	$not specified$
Check if Number Has Equal Digit Count and Digit Value	https://leetcode.com/problems/check-if-number-has-equal-digit-count-and-digit-value	Check if Number Has Equal Digit Count and Digit Value	$not specified$	$not specified$
Check if Numbers Are Ascending in a Sentence	https://leetcode.com/problems/check-if-numbers-are-ascending-in-a-sentence	Check if Numbers Are Ascending in a Sentence	$O(N)$	$O(N)$
Check if the Sentence Is Pangram	https://leetcode.com/problems/check-if-the-sentence-is-pangram/description/	Check if the Sentence Is Pangram	$not specified$	$not specified$
Check If Two String Arrays are Equivalent	https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent/	Check If Two String Arrays are Equivalent	$not specified$	$not specified$
Check if Word Equals Summation of Two Words	https://leetcode.com/problems/check-if-word-equals-summation-of-two-words/	Check if Word Equals Summation of Two Words	$not specified$	$not specified$
Check If N and Its Double Exist	https://leetcode.com/problems/check-if-n-and-its-double-exist	Check If N and Its Double Exist	$not specified$	$not specified$
Clear Digits	https://leetcode.com/problems/clear-digits	Clear Digits	$O(N)$	$O(N)$
Concatenation of Array	https://leetcode.com/problems/concatenation-of-array/	Concatenation of Array	$not specified$	$not specified$
Construct the Minimum Bitwise Array I	https://leetcode.com/problems/construct-the-minimum-bitwise-array-i	Construct the Minimum Bitwise Array I	$O(N * M)$	$O(N)$
Contains Duplicate	https://leetcode.com/problems/contains-duplicate	Contains Duplicate	$not specified$	$not specified$
Contains Duplicate II	https://leetcode.com/problems/contains-duplicate-ii	Contains Duplicate II	$O(N)$	$O(N)$
Convert Binary Number in a Linked List to Integer	https://leetcode.com/problems/convert-binary-number-in-a-linked-list-to-integer/	Convert Binary Number in a Linked List to Integer	$not specified$	$not specified$
Convert Date to Binary	https://leetcode.com/problems/convert-date-to-binary/	Convert Date to Binary	$O(N)$	$O(N)$
Convert the Temperature	https://leetcode.com/problems/convert-the-temperature/description/	Convert the Temperature	$not specified$	$not specified$
Count Asterisks	https://leetcode.com/problems/count-asterisks/	Count Asterisks	$not specified$	$not specified$
Count Common Words With One Occurrence	https://leetcode.com/problems/count-common-words-with-one-occurrence/	Count Common Words With One Occurrence	$not specified$	$not specified$
Count Complete Tree Nodes	https://leetcode.com/problems/count-complete-tree-nodes	Count Complete Tree Nodes	$O(N)$	$O(N)$
Count Elements With Maximum Frequency	https://leetcode.com/problems/count-elements-with-maximum-frequency/	Count Elements With Maximum Frequency	$not specified$	$not specified$
Count Equal and Divisible Pairs in an Array	https://leetcode.com/problems/count-equal-and-divisible-pairs-in-an-array/description/	Count Equal and Divisible Pairs in an Array	$not specified$	$not specified$
Counting Bits	https://leetcode.com/problems/counting-bits	Counting Bits	$not specified$	$not specified$
Counting Words With a Given Prefix	https://leetcode.com/problems/counting-words-with-a-given-prefix/	Counting Words With a Given Prefix	$not specified$	$not specified$
Count Items Matching a Rule	https://leetcode.com/problems/count-items-matching-a-rule/description/	Count Items Matching a Rule	$not specified$	$not specified$
Count Negative Numbers in a Sorted Matrix	https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix	Count Negative Numbers in a Sorted Matrix	$not specified$	$not specified$
Count Number of Pairs With Absolute Difference K	https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/description/	Count Number of Pairs With Absolute Difference K	$not specified$	$not specified$
Count Odd Numbers in an Interval Range	https://leetcode.com/problems/count-odd-numbers-in-an-interval-range	Count Odd Numbers in an Interval Range	$not specified$	$not specified$
Count of Matches in Tournament	https://leetcode.com/problems/count-of-matches-in-tournament/description/	Count of Matches in Tournament	$not specified$	$not specified$
Count Pairs Of Similar Strings	https://leetcode.com/problems/count-pairs-of-similar-strings	Count Pairs Of Similar Strings	$not specified$	$not specified$
Count Pairs That Form a Complete Day I	https://leetcode.com/problems/count-pairs-that-form-a-complete-day-i	Count Pairs That Form a Complete Day I	$O(N^2)$	$O(1)$
Count Pairs Whose Sum is Less than Target	https://leetcode.com/problems/count-pairs-whose-sum-is-less-than-target	Count Pairs Whose Sum is Less than Target	$O(N^2)$	$O(1)$
Count Prefixes of a Given String	https://leetcode.com/problems/count-prefixes-of-a-given-string	Count Prefixes of a Given String	$not specified$	$not specified$
Count Square Sum Triples	https://leetcode.com/problems/count-square-sum-triples	Count Square Sum Triples	$not specified$	$not specified$
Count Substrings That Satisfy K-Constraint I	https://leetcode.com/problems/count-substrings-that-satisfy-k-constraint-i	Count Substrings That Satisfy K-Constraint I	$O(N^2)$	$O(1)$
Count Symmetric Integers	https://leetcode.com/problems/count-symmetric-integers	Count Symmetric Integers	$O(N * Log_{10}M)$	$O(N * Log_{10}M)$
Count Tested Devices After Test Operations	https://leetcode.com/problems/count-tested-devices-after-test-operations	Count Tested Devices After Test Operations	$not specified$	$not specified$
Count the Digits That Divide a Number	https://leetcode.com/problems/count-the-digits-that-divide-a-number/description/	Count the Digits That Divide a Number	$not specified$	$not specified$
Count the Number of Consistent Strings	https://leetcode.com/problems/count-the-number-of-consistent-strings/	Count the Number of Consistent Strings	$not specified$	$not specified$
Count the Number of Vowel Strings in Range	https://leetcode.com/problems/count-the-number-of-vowel-strings-in-range/	Count the Number of Vowel Strings in Range	$not specified$	$not specified$
Count Vowel Substrings of a String	https://leetcode.com/problems/count-vowel-substrings-of-a-string/description/	Count Vowel Substrings of a String	$not specified$	$not specified$
Crawler Log Folder	https://leetcode.com/problems/crawler-log-folder	Crawler Log Folder	$O(N)$	$O(N)$
Create Target Array in the Given Order	https://leetcode.com/problems/create-target-array-in-the-given-order/description/	Create Target Array in the Given Order	$not specified$	$not specified$
Decode the Message	https://leetcode.com/problems/decode-the-message/	Decode the Message	$not specified$	$not specified$
Decode XORed Array	https://leetcode.com/problems/decode-xored-array/description/	Decode XORed Array	$not specified$	$not specified$
Decompress Run-Length Encoded List	https://leetcode.com/problems/decompress-run-length-encoded-list/	Decompress Run-Length Encoded List	$not specified$	$not specified$
Defanging an IP Address	https://leetcode.com/problems/defanging-an-ip-address/	Defanging an IP Address	$not specified$	$not specified$
Defuse the Bomb	https://leetcode.com/problems/defuse-the-bomb	Defuse the Bomb	$O(N * M)$	$O(N)$
Design an Ordered Stream	https://leetcode.com/problems/design-an-ordered-stream/description/	Design an Ordered Stream	$not specified$	$not specified$
Design HashMap	https://leetcode.com/problems/design-hashmap	Design HashMap	$not specified$	$not specified$
Design HashSet	https://leetcode.com/problems/design-hashset	Design HashSet	$not specified$	$not specified$
Design Neighbor Sum Service	https://leetcode.com/problems/design-neighbor-sum-service	Design Neighbor Sum Service	$O(N * M)$	$O(N * M)$
Determine Color of a Chessboard Square	https://leetcode.com/problems/determine-color-of-a-chessboard-square/	Determine Color of a Chessboard Square	$not specified$	$not specified$
Determine if String Halves Are Alike	https://leetcode.com/problems/determine-if-string-halves-are-alike/	Determine if String Halves Are Alike	$not specified$	$not specified$
Difference Between Element Sum and Digit Sum of an Array	https://leetcode.com/problems/difference-between-element-sum-and-digit-sum-of-an-array/	Difference Between Element Sum and Digit Sum of an Array	$not specified$	$not specified$
DI String Match	https://leetcode.com/problems/di-string-match/	DI String Match	$not specified$	$not specified$
Divide Array Into Equal Pairs	https://leetcode.com/problems/divide-array-into-equal-pairs/	Divide Array Into Equal Pairs	$not specified$	$not specified$
Divisible and Non-divisible Sums Difference	https://leetcode.com/problems/divisible-and-non-divisible-sums-difference	Divisible and Non-divisible Sums Difference	$not specified$	$not specified$
Evaluate Boolean Binary Tree	https://leetcode.com/problems/evaluate-boolean-binary-tree/solutions/	Evaluate Boolean Binary Tree	$not specified$	$not specified$
Faulty Keyboard	https://leetcode.com/problems/faulty-keyboard	Faulty Keyboard	$O(N^2)$	$O(N)$
Fibonacci Number	https://leetcode.com/problems/fibonacci-number/	Fibonacci Number	$not specified$	$not specified$
Final Array State After K Multiplication Operations I	https://leetcode.com/problems/final-array-state-after-k-multiplication-operations-i	Final Array State After K Multiplication Operations I	$O(N * M)$	$O(1)$
Final Prices With a Special Discount in a Shop	https://leetcode.com/problems/final-prices-with-a-special-discount-in-a-shop/	Final Prices With a Special Discount in a Shop	$not specified$	$not specified$
Final Value of Variable After Performing Operations	https://leetcode.com/problems/final-value-of-variable-after-performing-operations/	Final Value of Variable After Performing Operations	$not specified$	$not specified$
Find a Corresponding Node of a Binary Tree in a Clone of That Tree	https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree	Find a Corresponding Node of a Binary Tree in a Clone of That Tree	$O(N)$	$O(N)$
Find All Numbers Disappeared in an Array	https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array	Find All Numbers Disappeared in an Array	$not specified$	$not specified$
Find Center of Star Graph	https://leetcode.com/problems/find-center-of-star-graph/description/	Find Center of Star Graph	$not specified$	$not specified$
Find Closest Person	https://leetcode.com/problems/find-closest-person	Find Closest Person	$O(1)$	$O(1)$
Find Common Elements Between Two Arrays	https://leetcode.com/problems/find-common-elements-between-two-arrays	Find Common Elements Between Two Arrays	$not specified$	$not specified$
Find First Palindromic String in the Array	https://leetcode.com/problems/find-first-palindromic-string-in-the-array/	Find First Palindromic String in the Array	$not specified$	$not specified$
Find Greatest Common Divisor of Array	https://leetcode.com/problems/find-greatest-common-divisor-of-array/	Find Greatest Common Divisor of Array	$not specified$	$not specified$
Find if Digit Game Can Be Won	https://leetcode.com/problems/find-if-digit-game-can-be-won	Find if Digit Game Can Be Won	$O(N)$	$O(1)$
Find Indices of Stable Mountains	https://leetcode.com/problems/find-indices-of-stable-mountains	Find Indices of Stable Mountains	$O(N)$	$O(N)$
Find Maximum Number of String Pairs	https://leetcode.com/problems/find-maximum-number-of-string-pairs	Find Maximum Number of String Pairs	$O(N^2)$	$O(1)$
Find Minimum Operations to Make All Elements Divisible by Three	https://leetcode.com/problems/find-minimum-operations-to-make-all-elements-divisible-by-three/description/	Find Minimum Operations to Make All Elements Divisible by Three	$O(N)$	$O(1)$
Find Missing and Repeated Values	https://leetcode.com/problems/find-missing-and-repeated-values	Find Missing and Repeated Values	$O(N)$	$O(N$
Find Mode in Binary Search Tree	https://leetcode.com/problems/find-mode-in-binary-search-tree	Find Mode in Binary Search Tree	$O(N)$	$O(N)$
Find Most Frequent Vowel and Consonant	https://leetcode.com/problems/find-most-frequent-vowel-and-consonant	Find Most Frequent Vowel and Consonant	$O(N)$	$O(1)$
Find Nearest Point That Has the Same X or Y Coordinate	https://leetcode.com/problems/find-nearest-point-that-has-the-same-x-or-y-coordinate	Find Nearest Point That Has the Same X or Y Coordinate	$O(N)$	$O(1)$
Find Numbers with Even Number of Digits	https://leetcode.com/problems/find-numbers-with-even-number-of-digits/	Find Numbers with Even Number of Digits	$not specified$	$not specified$
Find N Unique Integers Sum up to Zero	https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero/	Find N Unique Integers Sum up to Zero	$not specified$	$not specified$
Find Pivot Index	https://leetcode.com/problems/find-pivot-index	Find Pivot Index	$O(N^2)$	$O(1)$
Find Target Indices After Sorting Array	https://leetcode.com/problems/find-target-indices-after-sorting-array/	Find Target Indices After Sorting Array	$not specified$	$not specified$
Find the Array Concatenation Value	https://leetcode.com/problems/find-the-array-concatenation-value/	Find the Array Concatenation Value	$not specified$	$not specified$
Find the Difference	https://leetcode.com/problems/find-the-difference	Find the Difference	$O(N)$	$O(1)$
Find the Difference of Two Arrays	https://leetcode.com/problems/find-the-difference-of-two-arrays	Find the Difference of Two Arrays	$not specified$	$not specified$
Find the Distance Value Between Two Arrays	https://leetcode.com/problems/find-the-distance-value-between-two-arrays	Find the Distance Value Between Two Arrays	$not specified$	$not specified$
Find the Distinct Difference Array	https://leetcode.com/problems/find-the-distinct-difference-array	Find the Distinct Difference Array	$not specified$	$not specified$
Find the Highest Altitude	https://leetcode.com/problems/find-the-highest-altitude/description/	Find the Highest Altitude	$not specified$	$not specified$
Find the Index of the First Occurrence in a String	https://leetcode.com/problems/find-the-index-of-the-first-occurrence-in-a-string/description/	Find the Index of the First Occurrence in a String	$not specified$	$not specified$
Find the Integer Added to Array I	https://leetcode.com/problems/find-the-integer-added-to-array-i	Find the Integer Added to Array I	$O(N * LogN)$	$O(1)$
Find the Key of the Numbers	https://leetcode.com/problems/find-the-key-of-the-numbers	Find the Key of the Numbers	$O(1)$	$O(1)$
Find the Maximum Achievable Number	https://leetcode.com/problems/find-the-maximum-achievable-number	Find the Maximum Achievable Number	$not specified$	$not specified$
Find the Number of Good Pairs I	https://leetcode.com/problems/find-the-number-of-good-pairs-i/description/	Find the Number of Good Pairs I	$O(N * M)$	$O(1)$
Find the Peaks	https://leetcode.com/problems/find-the-peaks	Find the Peaks	$not specified$	$not specified$
Find the Sum of Encrypted Integers	https://leetcode.com/problems/find-the-sum-of-encrypted-integers	Find the Sum of Encrypted Integers	$O(N)$	$O(1)$
Find the XOR of Numbers Which Appear Twice	https://leetcode.com/problems/find-the-xor-of-numbers-which-appear-twice/description/	Find the XOR of Numbers Which Appear Twice	$O(N)$	$O(N)$
Find Winner on a Tic Tac Toe Game	https://leetcode.com/problems/find-winner-on-a-tic-tac-toe-game	Find Winner on a Tic Tac Toe Game	$not specified$	$not specified$
Find Words Containing Character	https://leetcode.com/problems/find-words-containing-character	Find Words Containing Character	$not specified$	$not specified$
First Bad Version	https://leetcode.com/problems/first-bad-version	First Bad Version	$not specified$	$not specified$
First Letter to Appear Twice	https://leetcode.com/problems/first-letter-to-appear-twice/	First Letter to Appear Twice	$not specified$	$not specified$
First Unique Character in a String	https://leetcode.com/problems/first-unique-character-in-a-string	First Unique Character in a String	$not specified$	$not specified$
Fizz Buzz	https://leetcode.com/problems/fizz-buzz	Fizz Buzz	$not specified$	$not specified$
Flipping an Image	https://leetcode.com/problems/flipping-an-image	Flipping an Image	$O(N * M)$	$O(1)$
Generate a String With Characters That Have Odd Counts	https://leetcode.com/problems/generate-a-string-with-characters-that-have-odd-counts/description/	Generate a String With Characters That Have Odd Counts	$not specified$	$not specified$
Goal Parser Interpretation	https://leetcode.com/problems/goal-parser-interpretation/description/	Goal Parser Interpretation	$not specified$	$not specified$
Goat Latin	https://leetcode.com/problems/goat-latin	Goat Latin	$not specified$	$not specified$
Guess Number Higher or Lower	https://leetcode.com/problems/guess-number-higher-or-lower	Guess Number Higher or Lower	$not specified$	$not specified$
Hamming Distance	https://leetcode.com/problems/hamming-distance	Hamming Distance	$not specified$	$not specified$
Happy Number	https://leetcode.com/problems/happy-number	Happy Number	$O(N)$	$O(1)$
Harshad Number	https://leetcode.com/problems/harshad-number	Harshad Number	$LogN$	$O(1)$
Height Checker	https://leetcode.com/problems/height-checker	Height Checker	$not specified$	$not specified$
How Many Numbers Are Smaller Than the Current Number	https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number	How Many Numbers Are Smaller Than the Current Number	$not specified$	$not specified$
Implement Queue using Stacks	https://leetcode.com/problems/implement-queue-using-stacks/description	Implement Queue using Stacks	$O(N)$	$O(N)$
Implement Stack using Queues	https://leetcode.com/problems/implement-stack-using-queues/description/	Implement Stack using Queues	$O(N)$	$O(N)$
Increasing Order Search Tree	https://leetcode.com/problems/increasing-order-search-tree	Increasing Order Search Tree	$O(N)$	$LogN$
Intersection of Two Arrays	https://leetcode.com/problems/intersection-of-two-arrays/	Intersection of Two Arrays	$not specified$	$not specified$
Intersection of Two Arrays II	https://leetcode.com/problems/intersection-of-two-arrays-ii	Intersection of Two Arrays II	$not specified$	$not specified$
Intersection of Two Linked Lists	https://leetcode.com/problems/intersection-of-two-linked-lists	Intersection of Two Linked Lists	$O(M + N * LogM)$	$O(M)$
Island Perimeter	https://leetcode.com/problems/island-perimeter/	Island Perimeter	$not specified$	$not specified$
Isomorphic Strings	https://leetcode.com/problems/isomorphic-strings	Isomorphic Strings	$O(N)$	$O(N)$
Jewels and Stones	https://leetcode.com/problems/jewels-and-stones/	Jewels and Stones	$not specified$	$not specified$
Keep Multiplying Found Values by Two	https://leetcode.com/problems/keep-multiplying-found-values-by-two/	Keep Multiplying Found Values by Two	$not specified$	$not specified$
Keyboard Row	https://leetcode.com/problems/keyboard-row/	Keyboard Row	$not specified$	$not specified$
Kids With the Greatest Number of Candies	https://leetcode.com/problems/kids-with-the-greatest-number-of-candies/	Kids With the Greatest Number of Candies	$not specified$	$not specified$
Kth Distinct String in an Array	https://leetcode.com/problems/kth-distinct-string-in-an-array	Kth Distinct String in an Array	$not specified$	$not specified$
Largest 3-Same-Digit Number in String	https://leetcode.com/problems/largest-3-same-digit-number-in-string	Largest 3-Same-Digit Number in String	$not specified$	$not specified$
Largest Number At Least Twice of Others	https://leetcode.com/problems/largest-number-at-least-twice-of-others/	Largest Number At Least Twice of Others	$not specified$	$not specified$
Largest Perimeter Triangle	https://leetcode.com/problems/largest-perimeter-triangle	Largest Perimeter Triangle	$not specified$	$not specified$
Largest Positive Integer That Exists With Its Negative	https://leetcode.com/problems/largest-positive-integer-that-exists-with-its-negative/	Largest Positive Integer That Exists With Its Negative	$not specified$	$not specified$
Leaf-Similar Trees	https://leetcode.com/problems/leaf-similar-trees/description/	Leaf-Similar Trees	$not specified$	$not specified$
Lemonade Change	https://leetcode.com/problems/lemonade-change	Lemonade Change	$not specified$	$not specified$
Length of Last Word	https://leetcode.com/problems/length-of-last-word	Length of Last Word	$not specified$	$not specified$
Lexicographically Smallest Palindrome	https://leetcode.com/problems/lexicographically-smallest-palindrome	Lexicographically Smallest Palindrome	$O(N)$	$O(N)$
Linked List Cycle	https://leetcode.com/problems/linked-list-cycle	Linked List Cycle	$not specified$	$not specified$
Longest Common Prefix	https://leetcode.com/problems/longest-common-prefix	Longest Common Prefix	$not specified$	$not specified$
Longest Subsequence With Limited Sum	https://leetcode.com/problems/longest-subsequence-with-limited-sum/	Longest Subsequence With Limited Sum	$not specified$	$not specified$
Majority Element	https://leetcode.com/problems/majority-element	Majority Element	$O(N)$	$O(1)$
Make Array Zero by Subtracting Equal Amounts	https://leetcode.com/problems/make-array-zero-by-subtracting-equal-amounts	Make Array Zero by Subtracting Equal Amounts	$not specified$	$not specified$
Make The String Great	https://leetcode.com/problems/make-the-string-great	Make The String Great	$O(N)$	$O(N)$
Make Two Arrays Equal by Reversing Subarrays	https://leetcode.com/problems/make-two-arrays-equal-by-reversing-subarrays/	Make Two Arrays Equal by Reversing Subarrays	$not specified$	$not specified$
Matrix Diagonal Sum	https://leetcode.com/problems/matrix-diagonal-sum/description/	Matrix Diagonal Sum	$not specified$	$not specified$
Maximum 69 Number	https://leetcode.com/problems/maximum-69-number/	Maximum 69 Number	$not specified$	$not specified$
Maximum Count of Positive Integer and Negative Integer	https://leetcode.com/problems/maximum-count-of-positive-integer-and-negative-integer/	Maximum Count of Positive Integer and Negative Integer	$not specified$	$not specified$
Maximum Depth of Binary Tree	https://leetcode.com/problems/maximum-depth-of-binary-tree/	Maximum Depth of Binary Tree	$not specified$	$not specified$
Maximum Number of Balls in a Box	https://leetcode.com/problems/maximum-number-of-balls-in-a-box	Maximum Number of Balls in a Box	$not specified$	$not specified$
Maximum Number of Pairs in Array	https://leetcode.com/problems/maximum-number-of-pairs-in-array/	Maximum Number of Pairs in Array	$not specified$	$not specified$
Maximum Number of Words Found in Sentences	https://leetcode.com/problems/maximum-number-of-words-found-in-sentences/	Maximum Number of Words Found in Sentences	$not specified$	$not specified$
Maximum Number of Words You Can Type	https://leetcode.com/problems/maximum-number-of-words-you-can-type	Maximum Number of Words You Can Type	$not specified$	$not specified$
Maximum Odd Binary Number	https://leetcode.com/problems/maximum-odd-binary-number	Maximum Odd Binary Number	$not specified$	$not specified$
Maximum Product of Two Elements in an Array	https://leetcode.com/problems/maximum-product-of-two-elements-in-an-array/	Maximum Product of Two Elements in an Array	$not specified$	$not specified$
Maximum Strong Pair XOR I	https://leetcode.com/problems/maximum-strong-pair-xor-i	Maximum Strong Pair XOR I	$not specified$	$not specified$
Maximum Sum With Exactly K Elements	https://leetcode.com/problems/maximum-sum-with-exactly-k-elements/	Maximum Sum With Exactly K Elements	$not specified$	$not specified$
Maximum Units on a Truck	https://leetcode.com/problems/maximum-units-on-a-truck	Maximum Units on a Truck	$not specified$	$not specified$
Maximum Value of a String in an Array	https://leetcode.com/problems/maximum-value-of-a-string-in-an-array/	Maximum Value of a String in an Array	$not specified$	$not specified$
Merge Strings Alternately	https://leetcode.com/problems/merge-strings-alternately	Merge Strings Alternately	$not specified$	$not specified$
Merge Two 2D Arrays by Summing Values	https://leetcode.com/problems/merge-two-2d-arrays-by-summing-values/	Merge Two 2D Arrays by Summing Values	$not specified$	$not specified$
Merge Two Binary Trees	https://leetcode.com/problems/merge-two-binary-trees	Merge Two Binary Trees	$O(N)$	$O(N)$
Merge Two Sorted Lists	https://leetcode.com/problems/merge-two-sorted-lists	Merge Two Sorted Lists	$not specified$	$not specified$
Middle of the Linked List	https://leetcode.com/problems/middle-of-the-linked-list/description/	Middle of the Linked List	$not specified$	$not specified$
Minimize String Length	https://leetcode.com/problems/minimize-string-length	Minimize String Length	$O(N * LogN)$	$O(N)$
Minimum Absolute Difference	https://leetcode.com/problems/minimum-absolute-difference	Minimum Absolute Difference	$O(N * LogN)$	$O(N)$
Minimum Average of Smallest and Largest Elements	https://leetcode.com/problems/minimum-average-of-smallest-and-largest-elements	Minimum Average of Smallest and Largest Elements	$O(N * LogN)$	$O(N / 2)$
Minimum Cost to Reach Every Position	https://leetcode.com/problems/minimum-cost-to-reach-every-position	Minimum Cost to Reach Every Position	$O(N)$	$O(N)$
Minimum Depth of Binary Tree	https://leetcode.com/problems/minimum-depth-of-binary-tree	Minimum Depth of Binary Tree	$O(N)$	$O(N)$
Minimum Element After Replacement With Digit Sum	https://leetcode.com/problems/minimum-element-after-replacement-with-digit-sum	Minimum Element After Replacement With Digit Sum	$O(N * M)$	$O(1)$
Minimum Index Sum of Two Lists	https://leetcode.com/problems/minimum-index-sum-of-two-lists	Minimum Index Sum of Two Lists	$O(N)$	$O(N + M)$
Minimum Number Game	https://leetcode.com/problems/minimum-number-game	Minimum Number Game	$not specified$	$not specified$
Minimum Number of Chairs in a Waiting Room	https://leetcode.com/problems/minimum-number-of-chairs-in-a-waiting-room	Minimum Number of Chairs in a Waiting Room	$O(N)$	$O(1)$
Minimum Number of Moves to Seat Everyone	https://leetcode.com/problems/minimum-number-of-moves-to-seat-everyone/	Minimum Number of Moves to Seat Everyone	$not specified$	$not specified$
Minimum Operations to Exceed Threshold Value I	https://leetcode.com/problems/minimum-operations-to-exceed-threshold-value-i	Minimum Operations to Exceed Threshold Value I	$O(N)$	$O(1)$
Minimum Operations to Make Array Sum Divisible by K	https://leetcode.com/problems/minimum-operations-to-make-array-sum-divisible-by-k	Minimum Operations to Make Array Sum Divisible by K	$O(N)$	$O(1)$
Minimum String Length After Removing Substrings	https://leetcode.com/problems/minimum-string-length-after-removing-substrings	Minimum String Length After Removing Substrings	$O(N)$	$O(N)$
Minimum Sum of Four Digit Number After Splitting Digits	https://leetcode.com/problems/minimum-sum-of-four-digit-number-after-splitting-digits/	Minimum Sum of Four Digit Number After Splitting Digits	$not specified$	$not specified$
Minimum Value to Get Positive Step by Step Sum	https://leetcode.com/problems/minimum-value-to-get-positive-step-by-step-sum/	Minimum Value to Get Positive Step by Step Sum	$O(1)$	$O(1)$
Monotonic Array	https://leetcode.com/problems/monotonic-array	Monotonic Array	$not specified$	$not specified$
Move Zeroes	https://leetcode.com/problems/move-zeroes/description/	Move Zeroes	$O(N)$	$O(1)$
N-ary Tree Postorder Traversal	https://leetcode.com/problems/n-ary-tree-postorder-traversal/description/	N-ary Tree Postorder Traversal	$not specified$	$not specified$
N-ary Tree Preorder Traversal	https://leetcode.com/problems/n-ary-tree-preorder-traversal	N-ary Tree Preorder Traversal	$not specified$	$not specified$
Neither Minimum nor Maximum	https://leetcode.com/problems/neither-minimum-nor-maximum	Neither Minimum nor Maximum	$O(N)$	$O(1)$
Next Greater Element I	https://leetcode.com/problems/next-greater-element-i	Next Greater Element I	$not specified$	$not specified$
N-Repeated Element in Size 2N Array	https://leetcode.com/problems/n-repeated-element-in-size-2n-array/	N-Repeated Element in Size 2N Array	$not specified$	$not specified$
Number Complement	https://leetcode.com/problems/number-complement	Number Complement	$not specified$	$not specified$
Number of 1 Bits	https://leetcode.com/problems/number-of-1-bits	Number of 1 Bits	$O(1)$	$O(1)$
Number of Arithmetic Triplets	https://leetcode.com/problems/number-of-arithmetic-triplets/description/	Number of Arithmetic Triplets	$not specified$	$not specified$
Number of Changing Keys	https://leetcode.com/problems/number-of-changing-keys	Number of Changing Keys	$not specified$	$not specified$
Number of Common Factors	https://leetcode.com/problems/number-of-common-factors/description/	Number of Common Factors	$not specified$	$not specified$
Number of Employees Who Met the Target	https://leetcode.com/problems/number-of-employees-who-met-the-target/description/	Number of Employees Who Met the Target	$not specified$	$not specified$
Number of Even and Odd Bits	https://leetcode.com/problems/number-of-even-and-odd-bits	Number of Even and Odd Bits	$not specified$	$not specified$
Number of Good Pairs	https://leetcode.com/problems/number-of-good-pairs/	Number of Good Pairs	$O(N)$	$O(N)$
Number of Lines To Write String	https://leetcode.com/problems/number-of-lines-to-write-string	Number of Lines To Write String	$not specified$	$not specified$
Number of Recent Calls	https://leetcode.com/problems/number-of-recent-calls	Number of Recent Calls	$not specified$	$not specified$
Number Of Rectangles That Can Form The Largest Square	https://leetcode.com/problems/number-of-rectangles-that-can-form-the-largest-square/	Number Of Rectangles That Can Form The Largest Square	$not specified$	$not specified$
Number of Senior Citizens	https://leetcode.com/problems/number-of-senior-citizens	Number of Senior Citizens	$not specified$	$not specified$
Number of Steps to Reduce a Number to Zero	https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero/description/	Number of Steps to Reduce a Number to Zero	$not specified$	$not specified$
Number of Strings That Appear as Substrings in Word	https://leetcode.com/problems/number-of-strings-that-appear-as-substrings-in-word/description/	Number of Strings That Appear as Substrings in Word	$not specified$	$not specified$
Number of Students Doing Homework at a Given Time	https://leetcode.com/problems/number-of-students-doing-homework-at-a-given-time	Number of Students Doing Homework at a Given Time	$not specified$	$not specified$
Number of Unequal Triplets in Array	https://leetcode.com/problems/number-of-unequal-triplets-in-array	Number of Unequal Triplets in Array	$not specified$	$not specified$
Palindrome Linked List	https://leetcode.com/problems/palindrome-linked-list	Palindrome Linked List	$O(N)$	$O(1)$
Palindrome Number	https://leetcode.com/problems/palindrome-number/	Palindrome Number	$not specified$	$not specified$
Design Parking System	https://leetcode.com/problems/design-parking-system/	Design Parking System	$not specified$	$not specified$
Pascal's Triangle	https://leetcode.com/problems/pascals-triangle/	Pascal's Triangle	$not specified$	$not specified$
Pascal's Triangle II	https://leetcode.com/problems/pascals-triangle-ii/	Pascal's Triangle II	$O(N^2)$	$O(N)$
Path Sum	https://leetcode.com/problems/path-sum	Path Sum	$O(N)$	$O(N)$
Percentage of Letter in String	https://leetcode.com/problems/percentage-of-letter-in-string	Percentage of Letter in String	$not specified$	$not specified$
Permutation Difference between Two Strings	https://leetcode.com/problems/permutation-difference-between-two-strings	Permutation Difference between Two Strings	$O(N)$	$O(1)$
Plus One	https://leetcode.com/problems/plus-one	Plus One	$not specified$	$not specified$
Points That Intersect With Cars	https://leetcode.com/problems/points-that-intersect-with-cars	Points That Intersect With Cars	$O(N * M)$	$O(N)$
Power of Four	https://leetcode.com/problems/power-of-four	Power of Four	$not specified$	$not specified$
Prime Number of Set Bits in Binary Representation	https://leetcode.com/problems/prime-number-of-set-bits-in-binary-representation/	Prime Number of Set Bits in Binary Representation	$not specified$	$not specified$
Range Sum of BST	https://leetcode.com/problems/range-sum-of-bst/	Range Sum of BST	$not specified$	$not specified$
Remove Duplicates from Sorted Array	https://leetcode.com/problems/remove-duplicates-from-sorted-array/	Remove Duplicates from Sorted Array	$O(N)$	$O(1)$
Remove Element	https://leetcode.com/problems/remove-element/	Remove Element	$not specified$	$not specified$
Remove Linked List Elements	https://leetcode.com/problems/remove-linked-list-elements	Remove Linked List Elements	$O(N)$	$O(1)$
Remove Trailing Zeros From a String	https://leetcode.com/problems/remove-trailing-zeros-from-a-string	Remove Trailing Zeros From a String	$O(N)$	$O(N)$
Repeated Substring Pattern	https://leetcode.com/problems/repeated-substring-pattern	Repeated Substring Pattern	$not specified$	$not specified$
Replace All Digits with Characters	https://leetcode.com/problems/replace-all-digits-with-characters/description/	Replace All Digits with Characters	$not specified$	$not specified$
Replace Elements with Greatest Element on Right Side	https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side	Replace Elements with Greatest Element on Right Side	$O(N^2)$	$O(1)$
Reverse Degree of a String	https://leetcode.com/problems/reverse-degree-of-a-string	Reverse Degree of a String	$O(N)$	$O(1)$
Reverse Linked List	https://leetcode.com/problems/reverse-linked-list	Reverse Linked List	$O(N)$	$O(1)$
Reverse Prefix of Word	https://leetcode.com/problems/reverse-prefix-of-word/description/	Reverse Prefix of Word	$not specified$	$not specified$
Reverse String	https://leetcode.com/problems/reverse-string	Reverse String	$O(N)$	$O(1)$
Reverse Vowels of a String	https://leetcode.com/problems/reverse-vowels-of-a-string/description	Reverse Vowels of a String	$not specified$	$not specified$
Reverse Words in a String III	https://leetcode.com/problems/reverse-words-in-a-string-iii/description/	Reverse Words in a String III	$not specified$	$not specified$
Richest Customer Wealth	https://leetcode.com/problems/richest-customer-wealth/	Richest Customer Wealth	$not specified$	$not specified$
Rings and Rods	https://leetcode.com/problems/rings-and-rods/description/	Rings and Rods	$not specified$	$not specified$
Robot Return to Origin	https://leetcode.com/problems/robot-return-to-origin	Robot Return to Origin	$O(N)$	$O(1)$
Roman to Integer	https://leetcode.com/problems/roman-to-integer	Roman to Integer	$not specified$	$not specified$
Root Equals Sum of Children	https://leetcode.com/problems/root-equals-sum-of-children/	Root Equals Sum of Children	$not specified$	$not specified$
Row With Maximum Ones	https://leetcode.com/problems/row-with-maximum-ones/	Row With Maximum Ones	$not specified$	$not specified$
Running Sum of 1d Array	https://leetcode.com/problems/running-sum-of-1d-array/	Running Sum of 1d Array	$not specified$	$not specified$
Same Tree	https://leetcode.com/problems/same-tree	Same Tree	$O(N)$	$O(N)$
Score of a String	https://leetcode.com/problems/score-of-a-string	Score of a String	$O(N)$	$O(1)$
Search in a Binary Search Tree	https://leetcode.com/problems/search-in-a-binary-search-tree/description/	Search in a Binary Search Tree	$not specified$	$not specified$
Self Dividing Numbers	https://leetcode.com/problems/self-dividing-numbers/	Self Dividing Numbers	$not specified$	$not specified$
Separate the Digits in an Array	https://leetcode.com/problems/separate-the-digits-in-an-array/description/	Separate the Digits in an Array	$not specified$	$not specified$
Shuffle String	https://leetcode.com/problems/shuffle-string/description/	Shuffle String	$not specified$	$not specified$
Shuffle the Array	https://leetcode.com/problems/shuffle-the-array/	Shuffle the Array	$not specified$	$not specified$
Sign of the Product of an Array	https://leetcode.com/problems/sign-of-the-product-of-an-array	Sign of the Product of an Array	$O(N)$	$O(1)$
Single Number	https://leetcode.com/problems/single-number	Single Number	$O(N)$	$O(N)$
Smallest Even Multiple	https://leetcode.com/problems/smallest-even-multiple/	Smallest Even Multiple	$not specified$	$not specified$
Smallest Index With Equal Value	https://leetcode.com/problems/smallest-index-with-equal-value/	Smallest Index With Equal Value	$not specified$	$not specified$
Smallest Number With All Set Bits	https://leetcode.com/problems/smallest-number-with-all-set-bits	Smallest Number With All Set Bits	$O(1)$	$O(1)$
Snake in Matrix	https://leetcode.com/problems/snake-in-matrix	Snake in Matrix	$O(N)$	$O(1)$
Sort Array by Increasing Frequency	https://leetcode.com/problems/sort-array-by-increasing-frequency	Sort Array by Increasing Frequency	$not specified$	$not specified$
Sort Array By Parity	https://leetcode.com/problems/sort-array-by-parity/	Sort Array By Parity	$not specified$	$not specified$
Sorting the Sentence	https://leetcode.com/problems/sorting-the-sentence/description/	Sorting the Sentence	$not specified$	$not specified$
Sort Integers by The Number of 1 Bits	https://leetcode.com/problems/sort-integers-by-the-number-of-1-bits/	Sort Integers by The Number of 1 Bits	$not specified$	$not specified$
Sort the People	https://leetcode.com/problems/sort-the-people/	Sort the People	$not specified$	$not specified$
Special Array I	https://leetcode.com/problems/special-array-i	Special Array I	$O(N)$	$O(1)$
Split a String in Balanced Strings	https://leetcode.com/problems/split-a-string-in-balanced-strings/description/	Split a String in Balanced Strings	$not specified$	$not specified$
Squares of a Sorted Array	https://leetcode.com/problems/squares-of-a-sorted-array/	Squares of a Sorted Array	$O(N)$	$O(N)$
Subarrays Distinct Element Sum of Squares I	https://leetcode.com/problems/subarrays-distinct-element-sum-of-squares-i	Subarrays Distinct Element Sum of Squares I	$O(N^3)$	$O(N)$
Substrings of Size Three with Distinct Characters	https://leetcode.com/problems/substrings-of-size-three-with-distinct-characters	Substrings of Size Three with Distinct Characters	$not specified$	$not specified$
Subtract the Product and Sum of Digits of an Integer	https://leetcode.com/problems/subtract-the-product-and-sum-of-digits-of-an-integer/description/	Subtract the Product and Sum of Digits of an Integer	$not specified$	$not specified$
Sum Multiples	https://leetcode.com/problems/sum-multiples/	Sum Multiples	$not specified$	$not specified$
Sum of Digits in Base K	https://leetcode.com/problems/sum-of-digits-in-base-k	Sum of Digits in Base K	$not specified$	$not specified$
Sum of Digits of String After Convert	https://leetcode.com/problems/sum-of-digits-of-string-after-convert	Sum of Digits of String After Convert	$O(N * M)$	$O(N)$
Sum of Left Leaves	https://leetcode.com/problems/sum-of-left-leaves	Sum of Left Leaves	$O(N)$	$O(N)$
Sum of Squares of Special Elements	https://leetcode.com/problems/sum-of-squares-of-special-elements	Sum of Squares of Special Elements	$O(N)$	$O(1)$
Sum of Unique Elements	https://leetcode.com/problems/sum-of-unique-elements/	Sum of Unique Elements	$not specified$	$not specified$
Sum of Values at Indices With K Set Bits	https://leetcode.com/problems/sum-of-values-at-indices-with-k-set-bits/	Sum of Values at Indices With K Set Bits	$O(N)$	$O(1)$
Sum of Variable Length Subarrays	https://leetcode.com/problems/sum-of-variable-length-subarrays	Sum of Variable Length Subarrays	$O(N^2)$	$O(1)$
Symmetric Tree	https://leetcode.com/problems/symmetric-tree	Symmetric Tree	$O(N)$	$O(N * LogN)$
The K Weakest Rows in a Matrix	https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix	The K Weakest Rows in a Matrix	$not specified$	$not specified$
The Two Sneaky Numbers of Digitville	https://leetcode.com/problems/the-two-sneaky-numbers-of-digitville	The Two Sneaky Numbers of Digitville	$O(N)$	$O(N)$
Third Maximum Number	https://leetcode.com/problems/third-maximum-number	Third Maximum Number	$O(N)$	$O(1)$
Time Needed to Buy Tickets	https://leetcode.com/problems/time-needed-to-buy-tickets	Time Needed to Buy Tickets	$O(N * M)$	$O(1)$
To Lower Case	https://leetcode.com/problems/to-lower-case/description/	To Lower Case	$not specified$	$not specified$
Transform Array by Parity	https://leetcode.com/problems/transform-array-by-parity	Transform Array by Parity	$O(N * LogN)$	$LogN$
Truncate Sentence	https://leetcode.com/problems/truncate-sentence/	Truncate Sentence	$not specified$	$not specified$
Two Furthest Houses With Different Colors	https://leetcode.com/problems/two-furthest-houses-with-different-colors	Two Furthest Houses With Different Colors	$O(N^2)$	$O(1)$
Two Out of Three	https://leetcode.com/problems/two-out-of-three	Two Out of Three	$not specified$	$not specified$
Two Sum	https://leetcode.com/problems/two-sum/	Two Sum	$O(N)$	$O(1)$
Unique Morse Code Words	https://leetcode.com/problems/unique-morse-code-words/	Unique Morse Code Words	$not specified$	$not specified$
Unique Number of Occurrences	https://leetcode.com/problems/unique-number-of-occurrences/	Unique Number of Occurrences	$not specified$	$not specified$
Univalued Binary Tree	https://leetcode.com/problems/univalued-binary-tree/	Univalued Binary Tree	$not specified$	$not specified$
Valid Anagram	https://leetcode.com/problems/valid-anagram	Valid Anagram	$O(N * LogN)$	$O(N + M)$
Valid Mountain Array	https://leetcode.com/problems/valid-mountain-array/	Valid Mountain Array	$O(N)$	$O(1)$
Valid Palindrome	https://leetcode.com/problems/valid-palindrome	Valid Palindrome	$O(N)$	$O(1)$
Valid Parentheses	https://leetcode.com/problems/valid-parentheses	Valid Parentheses	$not specified$	$not specified$
Widest Vertical Area Between Two Points Containing No Points	https://leetcode.com/problems/widest-vertical-area-between-two-points-containing-no-points	Widest Vertical Area Between Two Points Containing No Points	$O(N * LogN)$	$LogN$
XOR Operation in an Array	https://leetcode.com/problems/xor-operation-in-an-array/description/	XOR Operation in an Array	$not specified$	$not specified$

MEDIUM

Name	Problem	Solution	Time Complexity	Space complexity
Add Two Numbers	https://leetcode.com/problems/add-two-numbers	Add Two Numbers	$O(N)$	$O(1)$
Add Two Numbers II	https://leetcode.com/problems/add-two-numbers-ii/description/?envType=study-plan-v2&envId=programming-skills	Add Two Numbers II	$not specified$	$not specified$
Binary Search Tree Iterator	https://leetcode.com/problems/binary-search-tree-iterator	Binary Search Tree Iterator	$not specified$	$not specified$
Binary Tree Level Order Traversal	https://leetcode.com/problems/binary-tree-level-order-traversal	Binary Tree Level Order Traversal	$not specified$	$not specified$
Copy List with Random Pointer	https://leetcode.com/problems/copy-list-with-random-pointer	Copy List with Random Pointer	$O(N)$	$O(N)$
Daily Temperatures	https://leetcode.com/problems/daily-temperatures	Daily Temperatures	$not specified$	$not specified$
Deepest Leaves Sum	https://leetcode.com/problems/deepest-leaves-sum/	Deepest Leaves Sum	$not specified$	$not specified$
Design Circular Queue	https://leetcode.com/problems/design-circular-queue	Design Circular Queue	$not specified$	$not specified$
Design Linked List	https://leetcode.com/problems/design-linked-list/	Design Linked List	$not specified$	$not specified$
Diagonal Traverse	https://leetcode.com/problems/diagonal-traverse	Diagonal Traverse	$not specified$	$not specified$
Evaluate Reverse Polish Notation	https://leetcode.com/problems/evaluate-reverse-polish-notation	Evaluate Reverse Polish Notation	$not specified$	$not specified$
Find The Original Array of Prefix Xor	https://leetcode.com/problems/find-the-original-array-of-prefix-xor/description/	Find The Original Array of Prefix Xor	$not specified$	$not specified$
Flatten a Multilevel Doubly Linked List	https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list	Flatten a Multilevel Doubly Linked List	$not specified$	$not specified$
Group Anagrams	https://leetcode.com/problems/group-anagrams/	Group Anagrams	$O(N * MLogM)$	$O(N)$
Insert Greatest Common Divisors in Linked List	https://leetcode.com/problems/insert-greatest-common-divisors-in-linked-list	Insert Greatest Common Divisors in Linked List	$O(N)$	$O(1)$
Integer Break	https://leetcode.com/problems/integer-break	Integer Break	$not specified$	$not specified$
Linked List Cycle II	https://leetcode.com/problems/linked-list-cycle-ii	Linked List Cycle II	$not specified$	$not specified$
Majority Element II	https://leetcode.com/problems/majority-element-ii	Majority Element II	$not specified$	$not specified$
Minimum Size Subarray Sum	https://leetcode.com/problems/minimum-size-subarray-sum	Minimum Size Subarray Sum	$not specified$	$not specified$
Min Stack	https://leetcode.com/problems/min-stack	Min Stack	$not specified$	$not specified$
Multiply Strings	https://leetcode.com/problems/multiply-strings	Multiply Strings	$not specified$	$not specified$
N-ary Tree Level Order Traversal	https://leetcode.com/problems/n-ary-tree-level-order-traversal	N-ary Tree Level Order Traversal	$not specified$	$not specified$
Number of Islands	https://leetcode.com/problems/number-of-islands	Number of Islands	$not specified$	$not specified$
Odd Even Linked List	https://leetcode.com/problems/odd-even-linked-list	Odd Even Linked List	$O(N)$	$O(1)$
Partitioning Into Minimum Number Of Deci-Binary Numbers	https://leetcode.com/problems/partitioning-into-minimum-number-of-deci-binary-numbers/description/	Partitioning Into Minimum Number Of Deci-Binary Numbers	$not specified$	$not specified$
Remove Colored Pieces if Both Neighbors are the Same Color	https://leetcode.com/problems/remove-colored-pieces-if-both-neighbors-are-the-same-color/	Remove Colored Pieces if Both Neighbors are the Same Color	$not specified$	$not specified$
Remove Nth Node From End of List	https://leetcode.com/problems/remove-nth-node-from-end-of-list	Remove Nth Node From End of List	$O(N)$	$O(1)$
Reverse Words in a String	https://leetcode.com/problems/reverse-words-in-a-string	Reverse Words in a String	$not specified$	$not specified$
Robot Bounded In Circle	https://leetcode.com/problems/robot-bounded-in-circle	Robot Bounded In Circle	$not specified$	$not specified$
Rotate Array	https://leetcode.com/problems/rotate-array	Rotate Array	$not specified$	$not specified$
Rotate List	https://leetcode.com/problems/rotate-list	Rotate List	$not specified$	$not specified$
Set Matrix Zeroes	https://leetcode.com/problems/set-matrix-zeroes	Set Matrix Zeroes	$not specified$	$not specified$
Spiral Matrix	https://leetcode.com/problems/spiral-matrix/	Spiral Matrix	$not specified$	$not specified$
Strictly Palindromic Number	https://leetcode.com/problems/strictly-palindromic-number/description/	Strictly Palindromic Number	$not specified$	$not specified$
Subrectangle Queries	https://leetcode.com/problems/subrectangle-queries/description/	Subrectangle Queries	$not specified$	$not specified$
Swap Nodes in Pairs	https://leetcode.com/problems/swap-nodes-in-pairs	Swap Nodes in Pairs	$not specified$	$not specified$
Two Sum II - Input Array Is Sorted	https://leetcode.com/problems/two-sum-ii-input-array-is-sorted	Two Sum II - Input Array Is Sorted	$O(N^2)$	$O(1)$
Validate Binary Search Tree	https://leetcode.com/problems/validate-binary-search-tree	Validate Binary Search Tree	$not specified$	$not specified$

Oracle

EASY

Name	Problem	Solution
Daily Leads and Partners	https://leetcode.com/problems/daily-leads-and-partners	Daily Leads and Partners
Fix Names in a Table	https://leetcode.com/problems/fix-names-in-a-table	Fix Names in a Table
Number of Unique Subjects Taught by Each Teacher	https://leetcode.com/problems/number-of-unique-subjects-taught-by-each-teacher	Number of Unique Subjects Taught by Each Teacher
Combine Two Tables	https://leetcode.com/problems/combine-two-tables	Combine Two Tables
Find Total Time Spent by Each Employee	https://leetcode.com/problems/find-total-time-spent-by-each-employee	Find Total Time Spent by Each Employee
Patients With a Condition	https://leetcode.com/problems/patients-with-a-condition	Patients With a Condition
Invalid Tweets	https://leetcode.com/problems/invalid-tweets	Invalid Tweets
Classes More Than 5 Students	https://leetcode.com/problems/classes-more-than-5-students	Classes More Than 5 Students
Triangle Judgement	https://leetcode.com/problems/triangle-judgement	Triangle Judgement
Biggest Single Number	https://leetcode.com/problems/biggest-single-number	Biggest Single Number
Customers Who Never Order	https://leetcode.com/problems/customers-who-never-order	Customers Who Never Order
Immediate Food Delivery I	https://leetcode.com/problems/immediate-food-delivery-i	Immediate Food Delivery I
Percentage of Users Attended a Contest	https://leetcode.com/problems/percentage-of-users-attended-a-contest	Percentage of Users Attended a Contest
Big Countries	https://leetcode.com/problems/big-countries	Big Countries
Employees Earning More Than Their Managers	https://leetcode.com/problems/employees-earning-more-than-their-managers	Employees Earning More Than Their Managers
Average Selling Price	https://leetcode.com/problems/average-selling-price	Average Selling Price
Students and Examinations	https://leetcode.com/problems/students-and-examinations	Students and Examinations
Not Boring Movies	https://leetcode.com/problems/not-boring-movies	Not Boring Movies
Actors and Directors Who Cooperated At Least Three Times	https://leetcode.com/problems/actors-and-directors-who-cooperated-at-least-three-times	Actors and Directors Who Cooperated At Least Three Times
Article Views I	https://leetcode.com/problems/article-views-i	Article Views I
Rising Temperature	https://leetcode.com/problems/rising-temperature	Rising Temperature
Queries Quality and Percentage	https://leetcode.com/problems/queries-quality-and-percentage	Queries Quality and Percentage
Sales Person	https://leetcode.com/problems/sales-person	Sales Person
Replace Employee ID With The Unique Identifier	https://leetcode.com/problems/replace-employee-id-with-the-unique-identifier	Replace Employee ID With The Unique Identifier
Average Time of Process per Machine	https://leetcode.com/problems/average-time-of-process-per-machine	Average Time of Process per Machine
Reformat Department Table	https://leetcode.com/problems/reformat-department-table	Reformat Department Table
Delete Duplicate Emails	https://leetcode.com/problems/delete-duplicate-emails	Delete Duplicate Emails
Recyclable and Low Fat Products	https://leetcode.com/problems/recyclable-and-low-fat-products	Recyclable and Low Fat Products
Customer Placing the Largest Number of Orders	https://leetcode.com/problems/customer-placing-the-largest-number-of-orders	Customer Placing the Largest Number of Orders
Customer Who Visited but Did Not Make Any Transactions	https://leetcode.com/problems/customer-who-visited-but-did-not-make-any-transactions	Customer Who Visited but Did Not Make Any Transactions
Swap Salary	https://leetcode.com/problems/swap-salary	Swap Salary
Duplicate Emails	https://leetcode.com/problems/duplicate-emails	Duplicate Emails
Calculate Special Bonus	https://leetcode.com/problems/calculate-special-bonus	Calculate Special Bonus
User Activity for the Past 30 Days I	https://leetcode.com/problems/user-activity-for-the-past-30-days-i	User Activity for the Past 30 Days I
Group Sold Products By The Date	https://leetcode.com/problems/group-sold-products-by-the-date	Group Sold Products By The Date
Employee Bonus	https://leetcode.com/problems/employee-bonus	Employee Bonus
Project Employees I	https://leetcode.com/problems/project-employees-i	Project Employees I
Find Customer Referee	https://leetcode.com/problems/find-customer-referee	Find Customer Referee
Bank Account Summary II	https://leetcode.com/problems/bank-account-summary-ii	Bank Account Summary II
The Number Of Rich Customers	https://leetcode.com/problems/the-number-of-rich-customers	The Number Of Rich Customers
Find Followers Count	https://leetcode.com/problems/find-followers-count	Find Followers Count
Rearrange Products Table	https://leetcode.com/problems/rearrange-products-table	Rearrange Products Table
Product Sales Analysis I	https://leetcode.com/problems/product-sales-analysis-i	Product Sales Analysis I
Game Play Analysis I	https://leetcode.com/problems/game-play-analysis-i	Game Play Analysis I
The Latest Login in 2020	https://leetcode.com/problems/the-latest-login-in-2020	The Latest Login in 2020
Employees With Missing Information	https://leetcode.com/problems/employees-with-missing-information	Employees With Missing Information
Sales Analysis III	https://leetcode.com/problems/sales-analysis-iii	Sales Analysis III
Top Travellers	https://leetcode.com/problems/top-travellers	Top Travellers

MEDIUM

Name	Problem	Solution
Capital Gain/Loss	https://leetcode.com/problems/capital-gainloss	Capital Gain/Loss
Confirmation Rate	https://leetcode.com/problems/confirmation-rate	Confirmation Rate
Tree Node	https://leetcode.com/problems/tree-node	Tree Node
Rank Scores	https://leetcode.com/problems/rank-scores	Rank Scores
Last Person to Fit in the Bus	https://leetcode.com/problems/last-person-to-fit-in-the-bus	Last Person to Fit in the Bus
Investments in 2016	https://leetcode.com/problems/investments-in-2016	Investments in 2016
Managers with at Least 5 Direct Reports	https://leetcode.com/problems/managers-with-at-least-5-direct-reports	Managers with at Least 5 Direct Reports
Monthly Transactions I	https://leetcode.com/problems/monthly-transactions-i	Monthly Transactions I
Exchange Seats	https://leetcode.com/problems/exchange-seats	Exchange Seats
Market Analysis I	https://leetcode.com/problems/market-analysis-i	Market Analysis I
Customers Who Bought All Products	https://leetcode.com/problems/customers-who-bought-all-products	Customers Who Bought All Products

Postgres

EASY

Name	Problem	Solution
Actors and Directors Who Cooperated At Least Three Times	https://leetcode.com/problems/actors-and-directors-who-cooperated-at-least-three-times	Actors and Directors Who Cooperated At Least Three Times