adding algo

src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_9.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 []

src/my_project/interviews/amazon_high_frequency_23/common_algos/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 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_3/optimal_partition_string.py

@@ -0,0 +1,16 @@
+class Solution:
+    def partitionString(self, s: str) -> int:
+
+        last_pos = [0] * 26
+        partitions = 0
+        last_end = 0
+
+        for i in range(len(s)):
+
+            if last_pos[ord(s[i]) - ord('a')] >= last_end:
+                partitions += 1
+                last_end = i + 1
+
+            last_pos[ord(s[i]) - ord('a')] = i + 1
+
+        return partitions

src/my_project/interviews/amazon_high_frequency_23/round_2/reorder_data_in_log_file_round_1.py → src/my_project/interviews/amazon_high_frequency_23/round_3/reorder_data_in_log_file_round_1.py

@@ -7,10 +7,12 @@ def reorderLogFiles(self, logs: List[str]) -> List[str]:
         digit_logs = []
 
         for log in logs:
-            _id, rest = log.split(' ', 1)
+            id_, rest = log.split(' ', 1)
             if rest[0].isdigit():
                 digit_logs.append(log)
             else:
-                letter_logs.append((rest, _id, log))
-        letter_logs.sort(key=lambda x: (x[0],x[1]))
-        return [orig for _,_,orig in letter_logs] + digit_logs
+                letter_logs.append((rest,id_,log))
+
+        # sort by content first, then identifier
+        letter_logs.sort(key=lambda x: (x[0], x[1]))
+        return [orig for _, _, orig in letter_logs] + digit_logs

src/my_project/interviews/top_150_questions_round_21/symmetric_tree.py

@@ -0,0 +1,32 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+class Solution:
+
+    def isSymmetric(self, root: TreeNode) -> bool:
+        return self.check_mirror(root1=root, root2=root) 
+
+    def check_mirror(self, root1: TreeNode, root2: TreeNode):
+
+        if root1 is None and root2 is None:
+            return True 
+        elif root1 is not None and root2 is not None:
+            try:
+                root1.val
+                root2.val
+            except:
+                return False 
+
+            if root1.val != root2.val:
+                return False 
+            else: 
+                return self.check_mirror(root1.left, root2.right) \
+                and self.check_mirror(root1.right, root2.left)
+        else:
+            return False 

tests/test_150_questions_round_21/test_symmetric_tree_round_21.py

@@ -0,0 +1,15 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_21\
+.symmetric_tree import Solution, TreeNode
+
+class SymmetricTreeTestCase(unittest.TestCase):
+
+    def test_is_symmetric(self):
+        solution = Solution()
+        output = solution.isSymmetric(TreeNode(1, TreeNode(7), TreeNode(7)))
+        self.assertTrue(output)
+
+    def test_is_no_symmetric(self):
+        solution = Solution()
+        output = solution.isSymmetric(TreeNode(1, TreeNode(2), TreeNode(3)))
+        self.assertFalse(output)