题解 | 守形数

#include <iostream>
using namespace std;

int main() {
    int n;
    while (cin >> n) {
        int count = 0, t = n;
        while (t) {
            count++;
            t /= 10;
        }
        t = 1;
        while (count--) {
            t *= 10;
        }
        if (n * n % t == n) {
            cout << "Yes!" << endl;
        } else {
            cout << "No!" << endl;
        }
    }
}
// 64 位输出请用 printf("%lld")