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 in = new Scanner(System.in);
        short n = in.nextShort();
        short m = in.nextShort();
        long aSum = 0;
        // 注意 hasNext 和 hasNextLine 的区别
        for(short i = 0; i < n; i++){
            for(short j = 0; j < m; j++){
                aSum += in.nextInt();
            }
        }
        System.out.println(aSum);
        in.close();
    }
}