SRM461 Div1 Easy

300
交互に(同じ色同士は触れない様に)使うという条件があるので、赤からと青からの2通りを試す。

int solve(double w, double h, vector<int> a, vector<int> b)
{
  vector<double> v;
  for(int i=0; i<min(a.size(), b.size()); ++i){
    v.push_back( a[i] );
    v.push_back( b[i] );
  }
  if( b.size() < a.size() )v.push_back( a[b.size()] );

  double sum = 0;
  for(int i=0; i<v.size(); ++i){
    if( v[i] < h )break;
    sum += sqrt( v[i] * v[i] - h * h );
    if( w <= sum )return i+1;
  }

  return -1;
}

class ColoringRectangle {
public:
  int chooseDisks(int width, int height, vector <int> red, vector <int> blue) {

    sort( ALL(red) );
    reverse( ALL(red) );

    sort( ALL(blue) );
    reverse( ALL(blue) );

    int a = solve( width, height, red, blue );
    int b = solve( width, height, blue, red );

    if( a == -1 && b == -1 )return -1;
    if( a == -1 )return b;
    if( b == -1 )return a;
    return min( a, b );
  }
};