编写程序，对下列3x3的整数矩阵，求其主，副对角线成员之和

Question

Answer 1

 
#include<stdio.h>
int main(void)
{
    int a[3][3]={{1,2,3,},{4,5,6},{7,8,9}};
    int i,j;
    int sum = 0;
    for(i = 0;i<3;i++)
    {
        for(j = 0;j<3;j++)
        {
            if((i == j)||(i+j==3-1))
            {
                sum += a[i][j];
            }
        }
    }
    printf("%d\n",sum);
    return 0;
}