From f1525634de1f02ed8beba85f63e63cba89e059a2 Mon Sep 17 00:00:00 2001
From: ivan <ivan1016017@gmail.com>
Date: Mon, 2 Feb 2026 04:49:33 -0600
Subject: [PATCH] adding algo

---
 .../common_algos/two_sum_round_4.py           | 19 ++++++++++++++
 .../common_algos/valid_palindrome_round_4.py  | 22 ++++++++++++++++
 ...maximum_sum_distinct_subarrays_lenght_k.py | 25 +++++++++++++++++++
 .../round_5/merge_intervals.py                | 17 +++++++++++++
 4 files changed, 83 insertions(+)
 create mode 100644 src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_4.py
 create mode 100644 src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_4.py
 create mode 100644 src/my_project/interviews/amazon_high_frequency_23/round_5/maximum_sum_distinct_subarrays_lenght_k.py
 create mode 100644 src/my_project/interviews/amazon_high_frequency_23/round_5/merge_intervals.py

diff --git a/src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_4.py b/src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_4.py
new file mode 100644
index 00000000..b642cdc8
--- /dev/null
+++ b/src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_4.py
@@ -0,0 +1,19 @@
+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 []
+
+
+
diff --git a/src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_4.py b/src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_4.py
new file mode 100644
index 00000000..0a9f8734
--- /dev/null
+++ b/src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_4.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 
\ No newline at end of file
diff --git a/src/my_project/interviews/amazon_high_frequency_23/round_5/maximum_sum_distinct_subarrays_lenght_k.py b/src/my_project/interviews/amazon_high_frequency_23/round_5/maximum_sum_distinct_subarrays_lenght_k.py
new file mode 100644
index 00000000..930e00b4
--- /dev/null
+++ b/src/my_project/interviews/amazon_high_frequency_23/round_5/maximum_sum_distinct_subarrays_lenght_k.py
@@ -0,0 +1,25 @@
+from typing import List, Union, Collection, Mapping, Optional
+
+class Solution:
+    def maximumSubarraySum(self, nums: List[int], k: int) -> int:
+        max_sum = 0
+        current_sum = 0
+        freq_sum = dict()
+        left = 0
+
+        for right in range(len(nums)):
+            current_sum += nums[right]
+
+            freq_sum[nums[right]] = freq_sum.get(nums[right], 0) + 1
+
+            if right - left > k - 1:
+                freq_sum[nums[left]] -= 1
+                if freq_sum[nums[left]] == 0:
+                    del freq_sum[nums[left]]
+                current_sum -= nums[left]
+                left += 1
+
+            if right - left == k - 1 and len(freq_sum) == k:
+                max_sum = max(max_sum, current_sum)
+
+        return max_sum
\ No newline at end of file
diff --git a/src/my_project/interviews/amazon_high_frequency_23/round_5/merge_intervals.py b/src/my_project/interviews/amazon_high_frequency_23/round_5/merge_intervals.py
new file mode 100644
index 00000000..e90ad800
--- /dev/null
+++ b/src/my_project/interviews/amazon_high_frequency_23/round_5/merge_intervals.py
@@ -0,0 +1,17 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def merge(self, intervals: List[List[int]]) -> List[List[int]]:
+
+        list_answer = list()
+
+        for i in sorted(intervals, key=lambda x: x[0]):
+
+            if list_answer and i[0] <= list_answer[-1][-1]:
+                list_answer[-1][-1] = max(list_answer[-1][-1], i[-1])
+            else:
+                list_answer.append(i)
+
+        return list_answer
+