练习7-7 矩阵运算

#include<stdio.h>

int main(void)
{
    int a[10][10];
    int n;

    scanf_s("%d", &n);

    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            scanf_s("%d", &a[i][j]);
        }
    }

    int sum = 0;

    for (int i = 0; i < n - 1; i++)
    {
        for (int j = 0; j < n - 1; j++)
        {
            if (i + j != n - 1)
            {
                sum=sum+a[i][j];
            }
        }
    }

    printf("%d
", sum);

    return 0;
}