二维数组/

输入M*N的矩阵，求外圈平均值
#include<stdio.h>
int main()
{
int arr[99][99]={};
int ave=0,m,n,k=0;
printf(“请输入M:”);
scanf("%d",&m);
printf(“请输入N:”);
scanf("%d",&n);
for (int i = 0; i < m; i++)
{
printf(“请输入第%d行：”,i+1);
for (int j = 0; j < n; j++)
{
scanf("%d",&arr[i][j]);
if(!i||!j||im-1||jn-1)
{
ave+=arr[i][j];
k++;
}
}
}
printf("%lf",(double)ave/k);
return 0;
}