Cod sursă (job #259887)

#include <fstream>

using namespace std;

ifstream fin("scv.in");
ofstream fout("scv.out");

int c,t,m,x,maxx,s,k;

inline void solve()
{
    maxx=m;
    while(s<x)
    {
        while(s<min(c,x))
        {
            k++;
            s+=m;
        }
        if(s+m*(t+(c/maxx))<x)
        {
            s=s-c+m*t;
            k+=t;
            m+=maxx;
        }
        else
        {
            k++;
            s+=m;
        }
    }
}

int main()
{
    fin>>c>>t>>m>>x;
    solve();
    fout<<k;
    return 0;
}