hdu 5373 The shortest problem

#include<bits/stdc++.h>
using namespace std;

int s[100],k;

int fnc(int x)
{
    int ret=0;
    while(x>0)
    {
        s[k++]=x%10;
        ret+=x%10;
        x/=10;
    }
    return ret;
}
int main()
{
    int _=0,n,m,tp,f,ans;
    while(~scanf("%d%d",&n,&m))
    {
        if(n==-1&&m==-1) break;
        ans=k=0;
        f=1;
        n=fnc(n);
        while(k--)
            if(f)
                ans+=s[k],f=0;
            else
                ans-=s[k],f=1;

        while(m--)
        {
            k=0;
            //printf("%d\n",n);
            n+=fnc(n);
            while(k--)
                if(f)
                    ans+=s[k],f=0;
                else
                    ans-=s[k],f=1;
        }
        printf("Case #%d: ",++_);
        if(ans<0) ans=-ans;
        if(ans%11==0) printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}