国王的魔镜题解

#include <bits/stdc++.h>
using namespace std;
int i,n,s;
string a,s1,s2,cl;
int main(){
    cin >> a;
    n = a.size();
    while(s1 == s2){
        s = s1.size();
        s1 = s2 = cl;
        for(i = 0;i < n / 2;i ++) s1 += a[i];
        for(i = n - 1;i >= n / 2;i --) s2 += a[i];
        n /= 2;
    }
    if(s) cout << s << endl;
    else cout << a.size() << endl;
    return 0;
}