纯小白，求大神帮忙解答～～

#include<stdio.h>

unsigned int fun (unsigned int n )
{
    unsigned int num=0;
    while(n>0)
    {
        num+=(n%10);
        num*=10;
        n/=10;
    }
    return num/10;
}

void main()
{

    unsigned int n,s;
    scanf("%u", &n);
    s=fun(n);
    
    printf("%u\n", s);

}