//C语言里面求余用%而不是/

#include <stdio.h>
int main()
{
    int arr[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%2==0)&&(j%2==0))
            {
                sum+=arr[i][j];
            }
            else if((i%2!=0)&&(j%2!=0))
            {
                sum+=arr[i][j];
            }
           
        }
    }
    printf("对角线元素之和是：%d\n",sum);
    return 0;   
}