题解 | 单组_二维数组

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

int main() {
    int n, m;
    cin >> n >> m;
    int a[n][m];
    for (int  i = 0; i < n; i++) {
        for (int  j = 0; j  < m; j++) {
            cin >> a[i][j];
        }

    }
    long long sum = 0;      //这里要longlong，后面很大
    for (int  i = 0; i < n; i++) {
        for (int j = 0; j < m ; j++) {
            sum += a[i][j];
        }

    }
    cout << sum;

}