// Problem   Drink// Algorithm Simulation// Runtime   O(1)// Author    Walter Guttmann// Date      24.01.2003#include <cassert>#include <fstream>#include <iostream>using namespace std;ifstream in ("drink.in");const double cw = 4.19;const double ci = 2.09;const double em = 335.0;int main (){  cout.setf(ios::fixed);  cout.precision(1);  while (1)  {    double mw, mi, tw, ti;    in >> mw >> mi >> tw >> ti;    if (mw == 0.0 && mi == 0.0 && tw == 0.0 && ti == 0.0)      break;    assert(mw >= 0.0 && mi >= 0.0 && mw + mi > 0.0);    assert(0.0 <= tw && tw < 100.0 && -30.0 < ti && ti <= 0.0);    double water0 = cw * mw * tw;    double ice0 = ci * mi * (- ti);    if (water0 <= ice0)    {      // cool water to zero      ice0 -= water0;      tw = 0.0;      ti = (- ice0) / (ci * mi);      // freeze some water      water0 = em * mw;      if (water0 <= ice0)      {        // freeze all water        ice0 -= water0;        ti = (- ice0) / (ci * mi);        // mw now denotes ice of temperature 0        // find equilibrium at temperature t where mi * t = mw * (tw - t)        ti = mi * ti / (mi + mw);        mi += mw;        mw = 0.0;      }      else      {        // heat ice to zero        ti = 0.0;        mw -= ice0 / em;        mi += ice0 / em;      }    }    else    {      // heat ice to zero      water0 -= ice0;      tw = water0 / (cw * mw);      ti = 0.0;      // melt some ice      ice0 = em * mi;      if (water0 <= ice0)      {        // cool water to zero        tw = 0.0;        mw += water0 / em;        mi -= water0 / em;      }      else      {        // melt all ice        water0 -= ice0;        tw = water0 / (cw * mw);        // mi now denotes water of temperature 0        // find equilibrium at temperature t where mi * t = mw * (tw - t)        tw = mw * tw / (mw + mi);        mw += mi;        mi = 0.0;      }    }    cout << mi << " g of ice and "         << mw << " g of water at "         << ti+tw << " C" << endl;  }  return 0;}