diff --git a/src/my_project/interviews/top_150_questions_round_22/ex_31_longest_substring_without_repeating_characters.py b/src/my_project/interviews/top_150_questions_round_22/ex_31_longest_substring_without_repeating_characters.py
new file mode 100644
index 00000000..e5519599
--- /dev/null
+++ b/src/my_project/interviews/top_150_questions_round_22/ex_31_longest_substring_without_repeating_characters.py
@@ -0,0 +1,22 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def lengthOfLongestSubstring(self, s: str) -> int:
+        char_index = {}
+        left = 0
+        max_length = 0
+        
+        for right in range(len(s)):
+            # If character seen before and in current window
+            if s[right] in char_index and char_index[s[right]] >= left:
+                # Move left pointer past the last occurrence
+                left = char_index[s[right]] + 1
+            
+            # Update last seen index of current character
+            char_index[s[right]] = right
+            
+            # Update max length
+            max_length = max(max_length, right - left + 1)
+        
+        return max_length
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diff --git a/src/my_project/interviews/top_150_questions_round_22/ex_32_substring_concat_all_words.py b/src/my_project/interviews/top_150_questions_round_22/ex_32_substring_concat_all_words.py
new file mode 100644
index 00000000..2c7afb23
--- /dev/null
+++ b/src/my_project/interviews/top_150_questions_round_22/ex_32_substring_concat_all_words.py
@@ -0,0 +1,9 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+import collections
+
+class Solution:
+    def findSubstring(self, s: str, words: List[str]) -> List[int]:
+        if not words: return []
+        LS, M, N, C = len(s), len(words), len(words[0]), collections.Counter(words)
+        return [i for i in range(LS-M*N+1) if collections.Counter([s[a:a+N] for a in range(i,i+M*N,N)]) == C]
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diff --git a/tests/test_150_questions_round_22/test_31_longest_substring_without_repeating_characters_round_22.py b/tests/test_150_questions_round_22/test_31_longest_substring_without_repeating_characters_round_22.py
new file mode 100644
index 00000000..196ddbb9
--- /dev/null
+++ b/tests/test_150_questions_round_22/test_31_longest_substring_without_repeating_characters_round_22.py
@@ -0,0 +1,17 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_31_longest_substring_without_repeating_characters import Solution
+
+class LongestSubstringUniqueCharactersTestCase(unittest.TestCase):
+
+    def test_first_pattern(self):
+        solution = Solution()
+        output = solution.lengthOfLongestSubstring(s = "abcabcbb")
+        target = 3 
+        self.assertEqual(output, target)
+
+    def test_second_pattern(self):
+        solution = Solution()
+        output = solution.lengthOfLongestSubstring(s = "bbbbb")
+        target = 1
+        self.assertEqual(output, target)
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diff --git a/tests/test_150_questions_round_22/test_32_substring_concat_all_words_round_22.py b/tests/test_150_questions_round_22/test_32_substring_concat_all_words_round_22.py
new file mode 100644
index 00000000..dca63851
--- /dev/null
+++ b/tests/test_150_questions_round_22/test_32_substring_concat_all_words_round_22.py
@@ -0,0 +1,17 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_22\
+.ex_32_substring_concat_all_words import Solution
+
+class SubstringConcatAllWordsTestCase(unittest.TestCase):
+
+    def test_first_pattern(self):
+        solution = Solution()
+        output = solution.findSubstring(s = "barfoothefoobarman", words = ["foo","bar"])
+        target = [0,9] 
+        self.assertEqual(output, target)
+
+    def test_second_pattern(self):
+        solution = Solution()
+        output = solution.findSubstring(s = "wordgoodgoodgoodbestword", words = ["word","good","best","word"])
+        target = []
+        self.assertEqual(output, target)
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