Cod sursă (job #227151)

#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;
    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;
    }
printf("%d",min);
return 0;
}