adding algo

Author: ivanpenaloza

src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_8.py

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+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_8.py

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+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_81_binary_tree_level_order_traversal.py

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+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 levelOrder(self, root: Optional[TreeNode]) -> List[List[int]]:
+        if not root:
+            return []
+
+        result = []
+        queue = deque([root])
+
+        while queue:
+            level_size = len(queue)
+            level = []
+            for _ in range(level_size):
+                node = queue.popleft()
+                level.append(node.val)
+                if node.left:
+                    queue.append(node.left)
+                if node.right:
+                    queue.append(node.right)
+            result.append(level)
+
+        return result

src/my_project/interviews_typescript/top_150_questions_round_1/ex_81_binary_tree_level_order_traversal.ts

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+import { TreeNode } from './TreeNode';     
+
+function levelOrder(root: TreeNode | null): number[][] {
+    if (!root) {
+        return [];
+    }
+
+    const result: number[][] = [];
+    const queue: TreeNode[] = [root];
+
+    while (queue.length > 0) {
+        const levelSize = queue.length;
+        const level: number[] = [];
+        
+        for (let i = 0; i < levelSize; i++) {
+            const node = queue.shift()!;
+            level.push(node.val);
+            
+            if (node.left) {
+                queue.push(node.left);
+            }
+            if (node.right) {
+                queue.push(node.right);
+            }
+        }
+        
+        result.push(level);
+    }
+
+    return result;
+}

tests/test_150_questions_round_22/test_81_binary_tree_level_order_traversal_round_22.py

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+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_81_binary_tree_level_order_traversal 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 = [3,9,20,null,null,15,7]
+        # Output: [[3],[9,20],[15,7]]
+        solution = Solution()
+        root = self.create_binary_tree([3, 9, 20, None, None, 15, 7])
+        result = solution.levelOrder(root)
+        self.assertEqual(result, [[3], [9, 20], [15, 7]])
+
+    def test_example_2(self):
+        # Example 2: Input: root = [1]
+        # Output: [[1]]
+        solution = Solution()
+        root = self.create_binary_tree([1])
+        result = solution.levelOrder(root)
+        self.assertEqual(result, [[1]])
+
+    def test_example_3(self):
+        # Example 3: Input: root = []
+        # Output: []
+        solution = Solution()
+        root = self.create_binary_tree([])
+        result = solution.levelOrder(root)
+        self.assertEqual(result, [])