C语言求助

int main()
{
    int a,b,c,i,m;
    int s=0,x=0;
    float s1,m1;
    scanf("%d %d",&a,&b);
    c=a/b;
    for (int i = b; i <= a; i += b)
        s += i;
    s1=s/c;
    printf("%.1f",s1);
    for(i=1;i<=a;i++)
    {
       x=x+i;
    }
    m=x-s;
    m1=m/(a-c);
        printf("%.1f",m1);
    return 0;
}