adding algo

src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_3.py

@@ -0,0 +1,21 @@
+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_3.py

@@ -0,0 +1,22 @@
+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_124_single_number_ii.py

@@ -0,0 +1,9 @@
+from typing import List 
+
+class Solution:
+    def singleNumber(self, nums: List[int]) -> int:
+        ones, twos = 0, 0
+        for n in nums:
+            ones = (ones ^ n) & ~twos
+            twos = (twos ^ n) & ~ones
+        return ones

src/my_project/interviews_typescript/top_150_questions_round_1/ex_124_single_number_ii.ts

@@ -0,0 +1,8 @@
+function singleNumberII(nums: number[]): number {
+    let ones = 0, twos = 0;
+    for (const n of nums) {
+        ones = (ones ^ n) & ~twos;
+        twos = (twos ^ n) & ~ones;
+    }
+    return ones;
+};

tests/test_150_questions_round_22/test_124_single_number_ii_round_22.py

@@ -0,0 +1,22 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_124_single_number_ii import Solution
+
+class SingleNumberIITestCase(unittest.TestCase):
+    def setUp(self):
+        self.solution = Solution()
+
+    def test_example_1(self):
+        self.assertEqual(self.solution.singleNumber([2, 2, 3, 2]), 3)
+
+    def test_example_2(self):
+        self.assertEqual(self.solution.singleNumber([0, 1, 0, 1, 0, 1, 99]), 99)
+
+    def test_single_element(self):
+        self.assertEqual(self.solution.singleNumber([1]), 1)
+
+    def test_negative_numbers(self):
+        self.assertEqual(self.solution.singleNumber([-2, -2, 1, -2]), 1)
+
+    def test_zero_is_single(self):
+        self.assertEqual(self.solution.singleNumber([5, 5, 5, 0]), 0)