#include <iostream> using namespace std; bool IsEqual(int num) { int ab = num / 100; int cd = num % 100; bool is_equal = ((ab + cd) *(ab + cd) == num); return is_equal; } int main() { /* 四位数ABCD中满足下述关系的数: (AB+CD)∗(AB+CD)=ABCD */ int num; cin >> num; for (int i = 1000; i <= num; i++) { if (IsEqual(i)) { cout << i << endl; } } return 0; }