Added tasks 508, 509, 511, 513.

Author: ThanhNIT

README.md

@@ -372,6 +372,7 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.8'
 
 | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
 |-|-|-|-|-|-
+| 0511 |[Game Play Analysis I](src/main/kotlin/g0501_0600/s0511_game_play_analysis_i/script.sql)| Easy | LeetCode_Curated_SQL_70, Database | 790 | 45.04
 
 #### Day 9 Control of Flow
 
@@ -447,6 +448,7 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.8'
 
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+| 0509 |[Fibonacci Number](src/main/kotlin/g0501_0600/s0509_fibonacci_number/Solution.kt)| Easy | Dynamic_Programming, Math, Recursion, Memoization | 139 | 82.72
 | 0070 |[Climbing Stairs](src.save/main/kotlin/g0001_0100/s0070_climbing_stairs/Solution.kt)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Memoization | 127 | 97.06
 
 #### Day 11 Dynamic Programming
@@ -777,6 +779,7 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.8'
 | 0152 |[Maximum Product Subarray](src.save/main/kotlin/g0101_0200/s0152_maximum_product_subarray/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming | 253 | 88.42
 | 0198 |[House Robber](src.save/main/kotlin/g0101_0200/s0198_house_robber/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming | 156 | 92.24
 | 0213 |[House Robber II](src.save/main/kotlin/g0201_0300/s0213_house_robber_ii/Solution.kt)| Medium | Array, Dynamic_Programming | 257 | 59.62
+| 0509 |[Fibonacci Number](src/main/kotlin/g0501_0600/s0509_fibonacci_number/Solution.kt)| Easy | Dynamic_Programming, Math, Recursion, Memoization | 139 | 82.72
 | 0070 |[Climbing Stairs](src.save/main/kotlin/g0001_0100/s0070_climbing_stairs/Solution.kt)| Easy | Top_100_Liked_Questions, Top_Interview_Questions, Dynamic_Programming, Math, Memoization | 127 | 97.06
 | 0064 |[Minimum Path Sum](src.save/main/kotlin/g0001_0100/s0064_minimum_path_sum/Solution.kt)| Medium | Top_100_Liked_Questions, Array, Dynamic_Programming, Matrix | 222 | 95.70
 | 0300 |[Longest Increasing Subsequence](src.save/main/kotlin/g0201_0300/s0300_longest_increasing_subsequence/Solution.kt)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Dynamic_Programming, Binary_Search | 318 | 82.28
@@ -1494,6 +1497,7 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.8'
 
 | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
 |-|-|-|-|-|-
+| 0509 |[Fibonacci Number](src/main/kotlin/g0501_0600/s0509_fibonacci_number/Solution.kt)| Easy | Dynamic_Programming, Math, Recursion, Memoization | 139 | 82.72
 
 #### Day 2
 
@@ -1641,6 +1645,10 @@ implementation 'com.github.javadev:leetcode-in-kotlin:1.8'
 | 0647 |[Palindromic Substrings](src/main/kotlin/g0601_0700/s0647_palindromic_substrings/Solution.kt)| Medium | Top_100_Liked_Questions, String, Dynamic_Programming | 266 | 67.83
 | 0560 |[Subarray Sum Equals K](src/main/kotlin/g0501_0600/s0560_subarray_sum_equals_k/Solution.kt)| Medium | Top_100_Liked_Questions, Array, Hash_Table, Prefix_Sum, Data_Structure_II_Day_5_Array | 692 | 53.27
 | 0543 |[Diameter of Binary Tree](src/main/kotlin/g0501_0600/s0543_diameter_of_binary_tree/Solution.kt)| Easy | Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree, Level_2_Day_7_Tree, Udemy_Tree_Stack_Queue | 307 | 43.93
+| 0513 |[Find Bottom Left Tree Value](src/main/kotlin/g0501_0600/s0513_find_bottom_left_tree_value/Solution.kt)| Medium | Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree | 190 | 88.24
+| 0511 |[Game Play Analysis I](src/main/kotlin/g0501_0600/s0511_game_play_analysis_i/script.sql)| Easy | LeetCode_Curated_SQL_70, Database, SQL_I_Day_8_Function | 790 | 45.04
+| 0509 |[Fibonacci Number](src/main/kotlin/g0501_0600/s0509_fibonacci_number/Solution.kt)| Easy | Dynamic_Programming, Math, Recursion, Memoization, Dynamic_Programming_I_Day_1, Level_1_Day_10_Dynamic_Programming, Udemy_Dynamic_Programming | 139 | 82.72
+| 0508 |[Most Frequent Subtree Sum](src/main/kotlin/g0501_0600/s0508_most_frequent_subtree_sum/Solution.kt)| Medium | Hash_Table, Depth_First_Search, Tree, Binary_Tree | 246 | 80.00
 | 0507 |[Perfect Number](src/main/kotlin/g0501_0600/s0507_perfect_number/Solution.kt)| Easy | Math | 172 | 81.82
 | 0506 |[Relative Ranks](src/main/kotlin/g0501_0600/s0506_relative_ranks/Solution.kt)| Easy | Array, Sorting, Heap_Priority_Queue | 244 | 94.23
 | 0504 |[Base 7](src/main/kotlin/g0501_0600/s0504_base_7/Solution.kt)| Easy | Math | 136 | 100.00

src/main/kotlin/g0501_0600/s0508_most_frequent_subtree_sum/Solution.kt

@@ -0,0 +1,39 @@
+package g0501_0600.s0508_most_frequent_subtree_sum
+
+// #Medium #Hash_Table #Depth_First_Search #Tree #Binary_Tree
+// #2023_01_10_Time_246_ms_(80.00%)_Space_38.4_MB_(93.33%)
+
+import com_github_leetcode.TreeNode
+
+/*
+ * Example:
+ * var ti = TreeNode(5)
+ * var v = ti.`val`
+ * Definition for a binary tree node.
+ * class TreeNode(var `val`: Int) {
+ *     var left: TreeNode? = null
+ *     var right: TreeNode? = null
+ * }
+ */
+class Solution {
+    private val cache = mutableMapOf<Int, Int>()
+
+    fun findFrequentTreeSum(root: TreeNode?): IntArray {
+        treeSum(root)
+        if (cache.isEmpty()) {
+            return IntArray(0)
+        }
+        val max = cache.maxBy { it.value }.value
+        return cache.filter { it.value == max }.map { it.key }.toIntArray()
+    }
+
+    private fun treeSum(node: TreeNode?): Int {
+        if (node == null) {
+            return 0
+        } else {
+            val sum = node.`val` + treeSum(node.left) + treeSum(node.right)
+            cache[sum] = cache.getOrDefault(sum, 0) + 1
+            return sum
+        }
+    }
+}

src/main/kotlin/g0501_0600/s0508_most_frequent_subtree_sum/readme.md

@@ -0,0 +1,28 @@
+508\. Most Frequent Subtree Sum
+
+Medium
+
+Given the `root` of a binary tree, return the most frequent **subtree sum**. If there is a tie, return all the values with the highest frequency in any order.
+
+The **subtree sum** of a node is defined as the sum of all the node values formed by the subtree rooted at that node (including the node itself).
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2021/04/24/freq1-tree.jpg)
+
+**Input:** root = [5,2,-3]
+
+**Output:** [2,-3,4]
+
+**Example 2:**
+
+![](https://assets.leetcode.com/uploads/2021/04/24/freq2-tree.jpg)
+
+**Input:** root = [5,2,-5]
+
+**Output:** [2]
+
+**Constraints:**
+
+*   The number of nodes in the tree is in the range <code>[1, 10<sup>4</sup>]</code>.
+*   <code>-10<sup>5</sup> <= Node.val <= 10<sup>5</sup></code>

src/main/kotlin/g0501_0600/s0509_fibonacci_number/Solution.kt

@@ -0,0 +1,22 @@
+package g0501_0600.s0509_fibonacci_number
+
+// #Easy #Dynamic_Programming #Math #Recursion #Memoization #Dynamic_Programming_I_Day_1
+// #Level_1_Day_10_Dynamic_Programming #Udemy_Dynamic_Programming
+// #2023_01_10_Time_139_ms_(82.72%)_Space_32.6_MB_(92.35%)
+
+class Solution {
+    private val memo = IntArray(31)
+    fun fib(n: Int): Int {
+        if (n == 0) {
+            return 0
+        }
+        if (n == 1) {
+            return 1
+        }
+        if (memo[n] != 0) {
+            return memo[n]
+        }
+        memo[n] = fib(n - 1) + fib(n - 2)
+        return memo[n]
+    }
+}

src/main/kotlin/g0501_0600/s0509_fibonacci_number/readme.md

@@ -0,0 +1,37 @@
+509\. Fibonacci Number
+
+Easy
+
+The **Fibonacci numbers**, commonly denoted `F(n)` form a sequence, called the **Fibonacci sequence**, such that each number is the sum of the two preceding ones, starting from `0` and `1`. That is,
+
+F(0) = 0, F(1) = 1 F(n) = F(n - 1) + F(n - 2), for n > 1.
+
+Given `n`, calculate `F(n)`.
+
+**Example 1:**
+
+**Input:** n = 2
+
+**Output:** 1
+
+**Explanation:** F(2) = F(1) + F(0) = 1 + 0 = 1.
+
+**Example 2:**
+
+**Input:** n = 3
+
+**Output:** 2
+
+**Explanation:** F(3) = F(2) + F(1) = 1 + 1 = 2.
+
+**Example 3:**
+
+**Input:** n = 4
+
+**Output:** 3
+
+**Explanation:** F(4) = F(3) + F(2) = 2 + 1 = 3.
+
+**Constraints:**
+
+*   `0 <= n <= 30`

src/main/kotlin/g0501_0600/s0511_game_play_analysis_i/readme.md

@@ -0,0 +1,50 @@
+511\. Game Play Analysis I
+
+Easy
+
+SQL Schema
+
+Table: `Activity`
+
+    +--------------+---------+
+    | Column Name  | Type    |
+    +--------------+---------+
+    | player_id    | int     |
+    | device_id    | int     |
+    | event_date   | date    |
+    | games_played | int     |
+    +--------------+---------+
+    (player_id, event_date) is the primary key of this table.
+    This table shows the activity of players of some games.
+    Each row is a record of a player who logged in and played a number of games (possibly 0) before logging out on someday using some device. 
+
+Write an SQL query to report the **first login date** for each player.
+
+Return the result table in **any order**.
+
+The query result format is in the following example.
+
+**Example 1:**
+
+**Input:**
+
+    Activity table:
+    +-----------+-----------+------------+--------------+
+    | player_id | device_id | event_date | games_played |
+    +-----------+-----------+------------+--------------+
+    | 1         | 2         | 2016-03-01 | 5            |
+    | 1         | 2         | 2016-05-02 | 6            |
+    | 2         | 3         | 2017-06-25 | 1            |
+    | 3         | 1         | 2016-03-02 | 0            |
+    | 3         | 4         | 2018-07-03 | 5            |
+    +-----------+-----------+------------+--------------+
+
+**Output:**
+
+    +-----------+-------------+
+    | player_id | first_login |
+    +-----------+-------------+
+    | 1         | 2016-03-01  |
+    | 2         | 2017-06-25  |
+    | 3         | 2016-03-02  |
+    +-----------+-------------+ 

src/main/kotlin/g0501_0600/s0511_game_play_analysis_i/script.sql

@@ -0,0 +1,6 @@
+# Write your MySQL query statement below
+# #Easy #LeetCode_Curated_SQL_70 #Database #SQL_I_Day_8_Function
+# #2023_01_10_Time_790_ms_(45.04%)_Space_0B_(100.00%)
+select distinct(player_id), min(event_date) as first_login
+from activity
+group by player_id

src/main/kotlin/g0501_0600/s0513_find_bottom_left_tree_value/Solution.kt

@@ -0,0 +1,53 @@
+package g0501_0600.s0513_find_bottom_left_tree_value
+
+// #Medium #Depth_First_Search #Breadth_First_Search #Tree #Binary_Tree
+// #2023_01_10_Time_190_ms_(88.24%)_Space_37.4_MB_(76.47%)
+
+import com_github_leetcode.TreeNode
+
+/*
+ * Example:
+ * var ti = TreeNode(5)
+ * var v = ti.`val`
+ * Definition for a binary tree node.
+ * class TreeNode(var `val`: Int) {
+ *     var left: TreeNode? = null
+ *     var right: TreeNode? = null
+ * }
+ */
+class Solution {
+    private fun func(root: TreeNode?, level: Int): IntArray? {
+        if (root!!.left == null && root.right == null) {
+            val a = IntArray(2)
+            a[0] = root.`val`
+            a[1] = level
+            return a
+        }
+        var a: IntArray? = null
+        var b: IntArray? = null
+        if (root.left != null) {
+            a = func(root.left, level + 1)
+        }
+        if (root.right != null) {
+            b = func(root.right, level + 1)
+        }
+        return if (a == null) {
+            b
+        } else if (b == null) {
+            a
+        } else {
+            if (a[1] >= b[1]) {
+                a
+            } else {
+                b
+            }
+        }
+    }
+
+    fun findBottomLeftValue(root: TreeNode?): Int {
+        val a = func(root, 0)
+        return if (a != null && a.size > 0) {
+            a[0]
+        } else -1
+    }
+}

src/main/kotlin/g0501_0600/s0513_find_bottom_left_tree_value/readme.md

@@ -0,0 +1,26 @@
+513\. Find Bottom Left Tree Value
+
+Medium
+
+Given the `root` of a binary tree, return the leftmost value in the last row of the tree.
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2020/12/14/tree1.jpg)
+
+**Input:** root = [2,1,3]
+
+**Output:** 1
+
+**Example 2:**
+
+![](https://assets.leetcode.com/uploads/2020/12/14/tree2.jpg)
+
+**Input:** root = [1,2,3,4,null,5,6,null,null,7]
+
+**Output:** 7
+
+**Constraints:**
+
+*   The number of nodes in the tree is in the range <code>[1, 10<sup>4</sup>]</code>.
+*   <code>-2<sup>31</sup> <= Node.val <= 2<sup>31</sup> - 1</code>

src/test/kotlin/g0501_0600/s0508_most_frequent_subtree_sum/SolutionTest.kt

@@ -0,0 +1,22 @@
+package g0501_0600.s0508_most_frequent_subtree_sum
+
+import com_github_leetcode.TreeNode
+import org.hamcrest.CoreMatchers.equalTo
+import org.hamcrest.MatcherAssert.assertThat
+import org.junit.jupiter.api.Test
+
+internal class SolutionTest {
+    @Test
+    fun findFrequentTreeSum() {
+        val treeNode: TreeNode = TreeNode.create(listOf(5, 2, -3))!!
+        val expected = intArrayOf(2, -3, 4)
+        assertThat(Solution().findFrequentTreeSum(treeNode), equalTo(expected))
+    }
+
+    @Test
+    fun findFrequentTreeSum2() {
+        val treeNode: TreeNode = TreeNode.create(listOf(5, 2, -5))!!
+        val expected = intArrayOf(2)
+        assertThat(Solution().findFrequentTreeSum(treeNode), equalTo(expected))
+    }
+}