Cod sursă (job #227159)

#include<cstdio>
int n,m,i,j,k,q,l,c,t,x,l1,l2,min,poz1,val1;
int main ()
{
freopen("scv.in","r",stdin);
freopen("scv.out","w",stdout);
scanf("%d%d%d%d",&c,&t,&n,&x);
min=x/n;
if(n*min<x)
    min++;
poz1=0;
val1=0;
for(i=1;i<=1000000&&poz1<min;i++)
    {
    int qq=x-val1;
    int op=qq/n/i;
    if(op*n*i<qq)
        op++;
    if(op+poz1<min)
        min=op+poz1;
    if(c>val1)
        {
        k=c-val1;
        q=n*i;
        int h=k/q;
        if(h*q<k)
            h++;
        val1=i*n*t+h*q-k;
        poz1=poz1+h+t;
        }
    else
        {
        val1=val1-c+i*n*t;
        poz1=poz1+t;
        }
    }
printf("%d",min);
return 0;
}