adding algo

Author: ivanpenaloza

src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_6.py

@@ -0,0 +1,18 @@
+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_6.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/amazon_high_frequency_23/round_6/lowest_common_ancestor_binary_tree_iv.py

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+from typing import List, Union, Collection, Mapping, Optional
+
+# Definition for a binary tree node.
+class TreeNode:
+    def __init__(self, x):
+        self.val = x
+        self.left = None
+        self.right = None
+
+class Solution:
+    def lowestCommonAncestor(self, root: TreeNode, nodes: List[TreeNode]) -> 'TreeNode':
+
+        node_set = set(nodes)
+
+        def dfs(node: TreeNode):
+
+            if not node or node in node_set:
+                return node 
+            
+            left = dfs(node.left)
+            right = dfs(node.right)
+
+            if left and right:
+                return node
+            
+            return left if left else right
+        
+        return dfs(root)