1037 在霍格沃茨找零钱 (20分)

#include <stdio.h>

int main()
{
    int g1,s1,k1,g2,s2,k2,g,s,k,g3,g4,s3,s4,k3,k4;
    scanf("%d.%d.%d %d.%d.%d",&g1,&s1,&k1,&g2,&s2,&k2);
    g3=g1;g4=g2;s3=s1;s4=s2;k3=k1;k4=k2;
    k=k2-k1;
    if(k<0)
    {
        s2--;
        k+=29;
    }
    s=s2-s1;
    if(s<0)
    {
        g2--;
        s+=17;
    }
    g=g2-g1;
    if(g<0)
    {
        k=k3-k4;
        if(k<0)
        {
            s3--;
            k+=29;
        }
        s=s3-s4;
        if(s<0)
        {
            g3--;
            s+=17;
        }
        g=g3-g4;
        printf("-%d.%d.%d\n",g,s,k);
    }
    else
        printf("%d.%d.%d\n",g,s,k);
    return 0;
}