#include <stdio.h>
int main()
{
int arr[3][3] = {{1,2,3},{4,5,6},{7,8,9}};
int i,j,k;
int sum=0;
for(i=0;i<3;i++)
{
for(j=0;j<3;j++)
{
if(i==0||2)
{
switch(j)
{
case 0:k=arr[i][j];break;
case 2:k=arr[i][j];break;
}
}
else
{
switch(j)
{
case 1:k=arr[i][j];break;
}
}
}
sum+=k;
}
printf("对角线元素之和是：%d\n",sum);
return 0;
}