最长回文子串(C++)

Posted 2022-02-01 hebbely

#include <iostream>

using namespace std;

bool validStr(string s,int left,int right)

    while (left < right) 
        if(s.at(left) != s.at(right))
            return false;
        left++;
        right--;
    
    return true;


string longestPalindrome(string s) 
    int len = s.length();
    int maxLen = 1;

    if(len < 2 )
    
        cout << s;
        return s;
    
    string res = s.substr(0,1);
    for (int i = 0; i < len - 1 ; i++) 
        for (int j = i + 1; j < len; j++) 
            if (j - i + 1 > maxLen && validStr(s, i, j)) 
                maxLen = j - i + 1;
                res = s.substr(i,maxLen);
            
        
    
    cout << res;
    return res;



int main()

    longestPalindrome("abc");
//    longestPalindrome("a");
//    longestPalindrome("abab");
//    longestPalindrome("abab78987");
//    longestPalindrome("aa678");
    return 0;