逆序输出

#include <stdio.h>int main(){   int i = 0;   int arr[9]={1,2,3,4,5,6,7,8,9};   int len=sizeof(arr)/sizeof(arr[0]);   int *l=arr;   int *r=arr+len-1; while( l < r ){    int tmp = *l;        *l = *r;        *r = tmp;        l++;        r--;}   for(i = 0;i<len;i++)    {printf("%d ",arr[i]);    }

return 0;}