solve 3

Author: lylaminju

longest-palindromic-substring/lylaminju.py

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+'''
+시간 복잡도: O(n^2)
+공간 복잡도: O(1)
+'''
+
+class Solution:
+    def longestPalindrome(self, s: str) -> str:
+        start, max_length = 0, 1  # Track longest palindrome
+
+        def expand_around_center(left: int, right: int) -> int:
+            while left >= 0 and right < len(s) and s[left] == s[right]:
+                left -= 1
+                right += 1
+            # Return length of palindrome
+            return right - left - 1
+        
+        # Check each position as potential center
+        for i in range(len(s)):
+            # Check for odd length palindromes (single character center)
+            len1 = expand_around_center(i, i)
+            # Check for even length palindromes (between two characters)
+            len2 = expand_around_center(i, i + 1)
+            
+            curr_max = max(len1, len2)
+            
+            # Update start and max_length if current palindrome is longer
+            if curr_max > max_length:
+                max_length = curr_max
+                start = i - (curr_max - 1) // 2
+        
+        return s[start:start + max_length]