poj 1563 The Snail

#include <iostream>#include <cmath>using namespace std;int        h, u, d, f,time1;double    now, speed;void work(){    while (1)    {        now += speed;        if (now > h)        { cout << "success on day " << time1 << endl; break;        }        now -= d;        if (now < 0)        { cout << "failure on day " << time1 << endl; break;        }        time1++;        speed -= u * f / 100.0;        if (speed < 0) speed = 0;    }}int main(){    while (cin >> h >> u >> d >> f && h != 0)    {        now = 0;        time1 = 1;        speed = u;        work();    }    return 0;}