Merge pull request #1554 from ivanpenaloza/february20

adding algo

Author: ivanpenaloza

src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_9.py

@@ -0,0 +1,22 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+
+        answer = dict()
+
+        for k, v in enumerate(nums):
+
+            if v in answer:
+                return [answer[v], k]
+            else:
+                answer[target - v] = k
+
+        return []    
+        
+
+
+
+
+

src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_9.py

@@ -0,0 +1,23 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+import re
+
+class Solution:
+    def isPalindrome(self, s: str) -> bool:
+
+        # To lowercase 
+        s = s.lower()
+
+        # Remove non-alphanumeric characters
+        s = re.sub(pattern=r'[^a-zA-Z0-9]', repl='', string=s)
+
+        # Determine if s is palindrome or not
+        len_s = len(s)
+
+        for i in range(len_s//2):
+
+            if s[i] != s[len_s - 1 - i]:
+                return False 
+            
+        return True 
+        

src/my_project/interviews/top_150_questions_round_22/ex_82_k_smallest_element_in_bst.py

@@ -0,0 +1,24 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+from collections import deque
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+class Solution:
+    def kthSmallest(self, root: TreeNode, k: int) -> int:
+        # Collect all values in sorted order using in-order traversal
+        values = []
+        
+        def inorder(node):
+            if not node:
+                return
+            inorder(node.left)
+            values.append(node.val)
+            inorder(node.right)
+        
+        inorder(root)
+        return values[k - 1]

src/my_project/interviews_typescript/top_150_questions_round_1/ex_82_k_smallest_element_in_bst.ts

@@ -0,0 +1,16 @@
+import { TreeNode } from './TreeNode';             
+
+function kthSmallest(root: TreeNode | null, k: number): number {
+    const result: number[] = [];
+    
+    function inorder(node: TreeNode | null): void {
+        if (!node) return;
+        
+        inorder(node.left);
+        result.push(node.val);
+        inorder(node.right);
+    }
+    
+    inorder(root);
+    return result[k - 1];
+}

tests/test_150_questions_round_22/test_82_k_smallest_element_in_bst_round_22.py

@@ -0,0 +1,50 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_82_k_smallest_element_in_bst import Solution, TreeNode
+
+class BinaryTreeLevelOrderTraversalTestCase(unittest.TestCase):
+
+    def create_binary_tree(self, values):
+        """
+        Helper function to create a binary tree from a list of values (level-order).
+        
+        :param values: List of node values (None represents null nodes)
+        :return: Root of the binary tree
+        """
+        if not values:
+            return None
+        
+        root = TreeNode(values[0])
+        queue = [root]
+        i = 1
+        
+        while queue and i < len(values):
+            node = queue.pop(0)
+            
+            if i < len(values) and values[i] is not None:
+                node.left = TreeNode(values[i])
+                queue.append(node.left)
+            i += 1
+            
+            if i < len(values) and values[i] is not None:
+                node.right = TreeNode(values[i])
+                queue.append(node.right)
+            i += 1
+        
+        return root
+
+    def test_example_1(self):
+        # Example 1: Input: root = [3,1,4,null,2], k = 1
+        # Output: 1
+        solution = Solution()
+        root = self.create_binary_tree([3, 1, 4, None, 2])
+        result = solution.kthSmallest(root, 1)
+        self.assertEqual(result, 1)
+
+    def test_example_2(self):
+        # Example 2: Input: root = [5,3,6,2,4,null,null,1], k = 3
+        # Output: 3
+        solution = Solution()
+        root = self.create_binary_tree([5, 3, 6, 2, 4, None, None, 1])
+        result = solution.kthSmallest(root, 3)
+        self.assertEqual(result, 3)