题解 | #单组_二维数组#

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

int main() {
    int n, m;
    cin >> n >> m;
    vector<vector<int>>arr;
    long long int sum = 0;
    while (n--) { // 注意 while 处理多个 case
        vector<int>subArr;
        for (int i = 1; i <= m; i++) {
            int a;
            cin >> a;
            subArr.push_back(a);
        }
        long long int subSum=0;
        for (auto subNode : subArr) {
            subSum += subNode;
        }
        sum+=subSum;
    }
    printf("%lld\n",sum);
}
// 64 位输出请用 printf("%lld")