Longest Palindromic Substring
Longest Palindromic Substring
Given a string s, find and return the longest substring that reads the same forward and backward (a palindrome). A substring is a contiguous sequence of characters within the string. If there are multiple palindromic substrings of the same maximum length, return the one that appears first (leftmost). Your solve(...) function receives these inputs directly as ready-made arguments — no input reading or parsing needed. Just compute and return the answer. Example: "babad" → "bab" (both "bab" and "aba" are valid; return first)
Input format — only if your code reads from stdin
Input format (stdin): - A single string s (no spaces) Output: the longest palindromic substring.
Approach
For each character (and each pair of adjacent characters), expand outward while the left and right characters match. Track the longest valid window found. This covers both odd-length and even-length palindromes.
Input
Output
- •
1 ≤ len(s) ≤ 1000, s contains only lowercase English letters
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