[백준] 1074 - Z(설명X)

#include <iostream>
using namespace std;
 
int main() {
    int N, r, c, x = 0, y = 0, index = 0;
    cin >> N >> r >> c;
    int num = 1;
    for (int i = 1; i < N; i++)
        num *= 2;
    while (num > 0) {
        if (r >= y + num) {
            y += num;
            index += num * num * 2;
        }
        if (c >= x + num) {
            x += num;
            index += num * num;
        }
 
        num /= 2;
    }
    cout << index << endl;
}