adding algo

Author: ivanpenaloza

src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_7.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_7.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_80_average_of_levels_in_binary_tree.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 averageOfLevels(self, root: Optional[TreeNode]) -> List[float]:
+        if not root:
+            return []
+        
+        q = deque()
+        q.append(root)
+        answer = list()
+
+
+        while q: 
+            qlen = len(q)
+            row = 0
+            for i in range(qlen):
+                root: Optional[TreeNode] = q.popleft()
+                row += root.val
+                if root.left: q.append(root.left)
+                if root.right: q.append(root.right)
+            answer.append(row/qlen)
+
+        return answer         

src/my_project/interviews_typescript/top_150_questions_round_1/ex_80_average_of_levels_in_binary_tree.ts

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

tests/test_150_questions_round_22/test_80_average_of_levels_in_binary_tree_round_22.py

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+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_80_average_of_levels_in_binary_tree import Solution, TreeNode
+
+class AverageOfLevelsInBinaryTreeTestCase(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: [3.00000,14.50000,11.00000]
+        # Explanation: The average value of nodes on level 0 is 3, 
+        # on level 1 is 14.5, and on level 2 is 11.
+        solution = Solution()
+        root = self.create_binary_tree([3, 9, 20, None, None, 15, 7])
+        result = solution.averageOfLevels(root)
+        expected = [3.00000, 14.50000, 11.00000]
+        self.assertEqual(len(result), len(expected))
+        for i in range(len(result)):
+            self.assertAlmostEqual(result[i], expected[i], places=5)
+
+    def test_example_2(self):
+        # Example 2: Input: root = [3,9,20,15,7]
+        # Output: [3.00000,14.50000,11.00000]
+        solution = Solution()
+        root = self.create_binary_tree([3, 9, 20, 15, 7])
+        result = solution.averageOfLevels(root)
+        expected = [3.00000, 14.50000, 11.00000]
+        self.assertEqual(len(result), len(expected))
+        for i in range(len(result)):
+            self.assertAlmostEqual(result[i], expected[i], places=5)
+
+    def test_empty_tree(self):
+        # Test with empty tree
+        # Output: []
+        solution = Solution()
+        root = self.create_binary_tree([])
+        result = solution.averageOfLevels(root)
+        self.assertEqual(result, [])
+
+    def test_single_node(self):
+        # Test with single node
+        # Input: root = [5]
+        # Output: [5.00000]
+        solution = Solution()
+        root = self.create_binary_tree([5])
+        result = solution.averageOfLevels(root)
+        expected = [5.00000]
+        self.assertEqual(len(result), len(expected))
+        for i in range(len(result)):
+            self.assertAlmostEqual(result[i], expected[i], places=5)