题解 | 单组_二维数组

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        long a[][] = new long[n][m];
        long sum  = 0;
        for(int i = 0;i< n;i++){
            for(int j = 0;j < m;j++){
                a[i][j] = sc.nextLong();
                sum = sum + a[i][j];
            }
        }
        System.out.println(sum);
        sc.close();
    }
}