adding algo

src/my_project/interviews/amazon_high_frequency_23/round_2/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='[^a-zA-Z0-9]', repl='', string=s)
+
+        # Determine if it 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_3/lowest_common_ancestor_binary_tree_iv.py

@@ -0,0 +1,29 @@
+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)
+

src/my_project/interviews/amazon_high_frequency_23/round_3/minimum_swaps_to_group_all_1_together.py

@@ -0,0 +1,21 @@
+from typing import List, Union, Collection, Mapping, Optional
+
+class Solution:
+    def minSwaps(self, data: List[int]) -> int:
+
+        # Window size 
+        k = sum(data)
+
+        answer = val = 0
+
+        for i, v in enumerate(data):
+
+            val += v 
+
+            if i >= k: 
+                val -= data[i - k]
+
+            if i >= k - 1:
+                answer = max(answer, val)
+
+        return k - answer

src/my_project/interviews/top_150_questions_round_21/two_sum.py

@@ -0,0 +1,16 @@
+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 -1

tests/test_150_questions_round_21/test_two_sum_round_21.py

@@ -0,0 +1,18 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_21\
+.two_sum import Solution
+
+class TwoSumTestCase(unittest.TestCase):
+
+    def test_is_two_sum(self):
+        solution = Solution()
+        output = solution.twoSum(nums=[2,7,11,15], target=9)
+        target = [0,1]
+        for k, v in enumerate(target):
+            self.assertEqual(v, output[k])
+
+    def test_is_no_two_sum(self):
+        solution = Solution()
+        output = solution.twoSum(nums=[2,7,11,15], target=0)
+        target = -1
+        self.assertEqual(output, target)