题解 | #最长回文子串#

#include <iostream>
using namespace std;

int findhui(string& s, int i){
    int res = 1;
    int j = i - 1;
    int k = i + 1;
    while(j >= 0 && k < s.size()){
        if(s[j] == s[k])
        res += 2;
        else break;
        j--;
        k++;
    }
    return res;
}

int findhui2(string& s, int i1, int i2){
    int res = 0;
    while(i1 >= 0 && i2 < s.size()){
        if(s[i1] == s[i2])
        res += 2;
        else break;
        i1--;
        i2++;
    }
    return res;
}

int main() {
    string s;
    cin >> s;
    int res1 = 0;
    int res2 = 0;
    for(int i = 0; i < s.size(); i++){
        res1 = max(res1, findhui(s, i));
        res2 = max(res2, findhui2(s, i, i + 1));
    }
    cout << max(res1, res2)<<endl;
    return 0;
}