feat: longest-unique-substring challenge

Author: IbatoLionDev

2-NORMAL/Python/3-longest-unique-substring/proposed-solution/main.py

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+# Challenge: Given a string, find the length of the longest substring without repeating characters.
+# Use sliding window techniques to optimize the solution's performance.
+
+def length_of_longest_substring(s):
+    char_index_map = {}
+    left = 0
+    max_length = 0
+    max_substring = ""
+
+    for right in range(len(s)):
+        if s[right] in char_index_map and char_index_map[s[right]] >= left:
+            left = char_index_map[s[right]] + 1
+        char_index_map[s[right]] = right
+        if right - left + 1 > max_length:
+            max_length = right - left + 1
+            max_substring = s[left:right+1]
+
+    return max_length, max_substring
+
+# Example usage
+if __name__ == "__main__":
+    test_string = "abcabcbb"
+    length, substring = length_of_longest_substring(test_string)
+    print(f"Length of longest substring without repeating characters: {length}")
+    print(f"Longest substring without repeating characters: {substring}")