题解 | 压缩二维码

#include <iostream>
#include <vector>
#include <cmath>
using namespace std;

int main() {
    int n, count = 0, sum = 0;//count计数器，每4位输出一次，值存在sum中
    char c;
    cin >> n;
    int length = pow(2,n);//取2的n次方
    for(int i = 0; i< length*length; i++){
        cin >> c;
        if(c=='.')
            sum += 0;
        else if(c=='#')
            sum += 1;
        count ++;
        if(count==4){
            cout << sum << ' ';
            sum = 0;
            count = 0;
        }
        else {
            sum *= 2;
        }
    }
    return 0;
}
// 64 位输出请用 printf("%lld")