编写一个函数，该函数接受一个int参数，并返回这个参数中打开

#include <stdio.h>
int count_on(int n);
int main(void)
{
 int n;
 printf("input a number(q to quit):");
 while( scanf("%d", &n) == 1 )
 {
 printf("%x----bit on number : %d\n", n, count_on(n) );
 printf("input a number(q to quit):");
 }
 printf("quit\n");
 return 0;
}
int count_on(int n)
{
 int count = 0;
 while( n/2 )
 {
 count += n%2;
 n = n >> 1;
 }
 count += n%2;
 return count;
}