题解 | #单组_二维数组#

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

int main() {
    int m, n;
    cin >> m >> n;
    vector<vector<long int>> v(m, vector<long int>(n)); // 创建一个 m x n 的二维向量

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

    long int sum = 0; 
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            sum += v[i][j]; 
        }
    }

    cout << sum << endl; 
    return 0;
}