Merge branch 'TheAlgorithms:master' into master

Author: akshaybsh

DIRECTORY.md

@@ -25,6 +25,7 @@
   * [Combination Sum](backtracking/combination_sum.py)
   * [Hamiltonian Cycle](backtracking/hamiltonian_cycle.py)
   * [Knight Tour](backtracking/knight_tour.py)
+  * [Match Word Pattern](backtracking/match_word_pattern.py)
   * [Minimax](backtracking/minimax.py)
   * [N Queens](backtracking/n_queens.py)
   * [N Queens Math](backtracking/n_queens_math.py)
@@ -50,6 +51,7 @@
   * [Index Of Rightmost Set Bit](bit_manipulation/index_of_rightmost_set_bit.py)
   * [Is Even](bit_manipulation/is_even.py)
   * [Is Power Of Two](bit_manipulation/is_power_of_two.py)
+  * [Largest Pow Of Two Le Num](bit_manipulation/largest_pow_of_two_le_num.py)
   * [Missing Number](bit_manipulation/missing_number.py)
   * [Numbers Different Signs](bit_manipulation/numbers_different_signs.py)
   * [Reverse Bits](bit_manipulation/reverse_bits.py)
@@ -198,6 +200,7 @@
     * [Red Black Tree](data_structures/binary_tree/red_black_tree.py)
     * [Segment Tree](data_structures/binary_tree/segment_tree.py)
     * [Segment Tree Other](data_structures/binary_tree/segment_tree_other.py)
+    * [Symmetric Tree](data_structures/binary_tree/symmetric_tree.py)
     * [Treap](data_structures/binary_tree/treap.py)
     * [Wavelet Tree](data_structures/binary_tree/wavelet_tree.py)
   * Disjoint Set
@@ -276,6 +279,7 @@
     * [Convolve](digital_image_processing/filters/convolve.py)
     * [Gabor Filter](digital_image_processing/filters/gabor_filter.py)
     * [Gaussian Filter](digital_image_processing/filters/gaussian_filter.py)
+    * [Laplacian Filter](digital_image_processing/filters/laplacian_filter.py)
     * [Local Binary Pattern](digital_image_processing/filters/local_binary_pattern.py)
     * [Median Filter](digital_image_processing/filters/median_filter.py)
     * [Sobel Filter](digital_image_processing/filters/sobel_filter.py)
@@ -322,6 +326,7 @@
   * [Integer Partition](dynamic_programming/integer_partition.py)
   * [Iterating Through Submasks](dynamic_programming/iterating_through_submasks.py)
   * [Knapsack](dynamic_programming/knapsack.py)
+  * [Largest Divisible Subset](dynamic_programming/largest_divisible_subset.py)
   * [Longest Common Subsequence](dynamic_programming/longest_common_subsequence.py)
   * [Longest Common Substring](dynamic_programming/longest_common_substring.py)
   * [Longest Increasing Subsequence](dynamic_programming/longest_increasing_subsequence.py)
@@ -363,8 +368,10 @@
   * [Ind Reactance](electronics/ind_reactance.py)
   * [Ohms Law](electronics/ohms_law.py)
   * [Real And Reactive Power](electronics/real_and_reactive_power.py)
+  * [Resistor Color Code](electronics/resistor_color_code.py)
   * [Resistor Equivalence](electronics/resistor_equivalence.py)
   * [Resonant Frequency](electronics/resonant_frequency.py)
+  * [Wheatstone Bridge](electronics/wheatstone_bridge.py)
 
 ## File Transfer
   * [Receive File](file_transfer/receive_file.py)
@@ -413,6 +420,7 @@
   * [Check Bipartite Graph Dfs](graphs/check_bipartite_graph_dfs.py)
   * [Check Cycle](graphs/check_cycle.py)
   * [Connected Components](graphs/connected_components.py)
+  * [Deep Clone Graph](graphs/deep_clone_graph.py)
   * [Depth First Search](graphs/depth_first_search.py)
   * [Depth First Search 2](graphs/depth_first_search_2.py)
   * [Dijkstra](graphs/dijkstra.py)
@@ -460,6 +468,7 @@
 ## Greedy Methods
   * [Fractional Knapsack](greedy_methods/fractional_knapsack.py)
   * [Fractional Knapsack 2](greedy_methods/fractional_knapsack_2.py)
+  * [Gas Station](greedy_methods/gas_station.py)
   * [Minimum Waiting Time](greedy_methods/minimum_waiting_time.py)
   * [Optimal Merge Pattern](greedy_methods/optimal_merge_pattern.py)
 
@@ -542,6 +551,7 @@
   * [Average Median](maths/average_median.py)
   * [Average Mode](maths/average_mode.py)
   * [Bailey Borwein Plouffe](maths/bailey_borwein_plouffe.py)
+  * [Base Neg2 Conversion](maths/base_neg2_conversion.py)
   * [Basic Maths](maths/basic_maths.py)
   * [Bell Numbers](maths/bell_numbers.py)
   * [Binary Exp Mod](maths/binary_exp_mod.py)
@@ -657,7 +667,6 @@
     * [P Series](maths/series/p_series.py)
   * [Sieve Of Eratosthenes](maths/sieve_of_eratosthenes.py)
   * [Sigmoid](maths/sigmoid.py)
-  * [Sigmoid Linear Unit](maths/sigmoid_linear_unit.py)
   * [Signum](maths/signum.py)
   * [Simpson Rule](maths/simpson_rule.py)
   * [Simultaneous Linear Equation Solver](maths/simultaneous_linear_equation_solver.py)
@@ -716,6 +725,7 @@
     * [Leaky Rectified Linear Unit](neural_network/activation_functions/leaky_rectified_linear_unit.py)
     * [Rectified Linear Unit](neural_network/activation_functions/rectified_linear_unit.py)
     * [Scaled Exponential Linear Unit](neural_network/activation_functions/scaled_exponential_linear_unit.py)
+    * [Sigmoid Linear Unit](neural_network/activation_functions/sigmoid_linear_unit.py)
   * [Back Propagation Neural Network](neural_network/back_propagation_neural_network.py)
   * [Convolution Neural Network](neural_network/convolution_neural_network.py)
   * [Perceptron](neural_network/perceptron.py)
@@ -1155,6 +1165,7 @@
   * [Autocomplete Using Trie](strings/autocomplete_using_trie.py)
   * [Barcode Validator](strings/barcode_validator.py)
   * [Boyer Moore Search](strings/boyer_moore_search.py)
+  * [Camel Case To Snake Case](strings/camel_case_to_snake_case.py)
   * [Can String Be Rearranged As Palindrome](strings/can_string_be_rearranged_as_palindrome.py)
   * [Capitalize](strings/capitalize.py)
   * [Check Anagrams](strings/check_anagrams.py)
@@ -1180,6 +1191,7 @@
   * [Naive String Search](strings/naive_string_search.py)
   * [Ngram](strings/ngram.py)
   * [Palindrome](strings/palindrome.py)
+  * [Pig Latin](strings/pig_latin.py)
   * [Prefix Function](strings/prefix_function.py)
   * [Rabin Karp](strings/rabin_karp.py)
   * [Remove Duplicate](strings/remove_duplicate.py)

backtracking/match_word_pattern.py

@@ -0,0 +1,61 @@
+def match_word_pattern(pattern: str, input_string: str) -> bool:
+    """
+    Determine if a given pattern matches a string using backtracking.
+
+    pattern: The pattern to match.
+    input_string: The string to match against the pattern.
+    return: True if the pattern matches the string, False otherwise.
+
+    >>> match_word_pattern("aba", "GraphTreesGraph")
+    True
+
+    >>> match_word_pattern("xyx", "PythonRubyPython")
+    True
+
+    >>> match_word_pattern("GG", "PythonJavaPython")
+    False
+    """
+
+    def backtrack(pattern_index: int, str_index: int) -> bool:
+        """
+        >>> backtrack(0, 0)
+        True
+
+        >>> backtrack(0, 1)
+        True
+
+        >>> backtrack(0, 4)
+        False
+        """
+        if pattern_index == len(pattern) and str_index == len(input_string):
+            return True
+        if pattern_index == len(pattern) or str_index == len(input_string):
+            return False
+        char = pattern[pattern_index]
+        if char in pattern_map:
+            mapped_str = pattern_map[char]
+            if input_string.startswith(mapped_str, str_index):
+                return backtrack(pattern_index + 1, str_index + len(mapped_str))
+            else:
+                return False
+        for end in range(str_index + 1, len(input_string) + 1):
+            substr = input_string[str_index:end]
+            if substr in str_map:
+                continue
+            pattern_map[char] = substr
+            str_map[substr] = char
+            if backtrack(pattern_index + 1, end):
+                return True
+            del pattern_map[char]
+            del str_map[substr]
+        return False
+
+    pattern_map: dict[str, str] = {}
+    str_map: dict[str, str] = {}
+    return backtrack(0, 0)
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()

data_structures/binary_tree/symmetric_tree.py

@@ -0,0 +1,101 @@
+"""
+Given the root of a binary tree, check whether it is a mirror of itself
+(i.e., symmetric around its center).
+
+Leetcode reference: https://leetcode.com/problems/symmetric-tree/
+"""
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass
+class Node:
+    """
+    A Node has data variable and pointers to Nodes to its left and right.
+    """
+
+    data: int
+    left: Node | None = None
+    right: Node | None = None
+
+
+def make_symmetric_tree() -> Node:
+    r"""
+    Create a symmetric tree for testing.
+    The tree looks like this:
+           1
+         /   \
+        2     2
+      / \    / \
+     3   4   4  3
+    """
+    root = Node(1)
+    root.left = Node(2)
+    root.right = Node(2)
+    root.left.left = Node(3)
+    root.left.right = Node(4)
+    root.right.left = Node(4)
+    root.right.right = Node(3)
+    return root
+
+
+def make_asymmetric_tree() -> Node:
+    r"""
+    Create a asymmetric tree for testing.
+    The tree looks like this:
+           1
+         /   \
+        2     2
+      / \    / \
+     3   4   3  4
+    """
+    root = Node(1)
+    root.left = Node(2)
+    root.right = Node(2)
+    root.left.left = Node(3)
+    root.left.right = Node(4)
+    root.right.left = Node(3)
+    root.right.right = Node(4)
+    return root
+
+
+def is_symmetric_tree(tree: Node) -> bool:
+    """
+    Test cases for is_symmetric_tree function
+    >>> is_symmetric_tree(make_symmetric_tree())
+    True
+    >>> is_symmetric_tree(make_asymmetric_tree())
+    False
+    """
+    if tree:
+        return is_mirror(tree.left, tree.right)
+    return True  # An empty tree is considered symmetric.
+
+
+def is_mirror(left: Node | None, right: Node | None) -> bool:
+    """
+    >>> tree1 = make_symmetric_tree()
+    >>> tree1.right.right = Node(3)
+    >>> is_mirror(tree1.left, tree1.right)
+    True
+    >>> tree2 = make_asymmetric_tree()
+    >>> is_mirror(tree2.left, tree2.right)
+    False
+    """
+    if left is None and right is None:
+        # Both sides are empty, which is symmetric.
+        return True
+    if left is None or right is None:
+        # One side is empty while the other is not, which is not symmetric.
+        return False
+    if left.data == right.data:
+        # The values match, so check the subtree
+        return is_mirror(left.left, right.right) and is_mirror(left.right, right.left)
+    return False
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()