Cod sursă (job #371510)

#include <fstream>

using namespace std;
int c,t,m,x,nr,sm,ok;
int main()
{
    ifstream fin("scv.in");
    ofstream fout("scv.out");
    fin>>c>>t>>m>>x;
    sm=0;
    nr=1;
    ok=0;
    while(sm<x)
    {
        while(sm<x&&sm<c)
        {
            sm+=m*nr;
            ok++;
        }
        if (sm + nr*m*t + m*nr *(c/m)< x)
        {
            ok+=t;
            sm+=t*nr*m-c;
            nr++;
        }
        else
            while(sm<x)
            {
                sm+=nr*m;
                ok++;

            }
    }

    fout<<ok;
    return 0;
}