/* $Id: ClpConstraintLinear.cpp 1402 2009-07-25 08:39:55Z forrest $ */
// Copyright (C) 2007, International Business Machines
// Corporation and others.  All Rights Reserved.

#include "CoinPragma.hpp"
#include "CoinHelperFunctions.hpp"
#include "CoinIndexedVector.hpp"
#include "ClpSimplex.hpp"
#include "ClpConstraintLinear.hpp"
#include "CoinSort.hpp"
//#############################################################################
// Constructors / Destructor / Assignment
//#############################################################################

//-------------------------------------------------------------------
// Default Constructor 
//-------------------------------------------------------------------
ClpConstraintLinear::ClpConstraintLinear () 
: ClpConstraint()
{
  type_=0;
  column_=NULL;
  coefficient_ = NULL;
  numberColumns_=0;
  numberCoefficients_=0;
}

//-------------------------------------------------------------------
// Useful Constructor 
//-------------------------------------------------------------------
ClpConstraintLinear::ClpConstraintLinear (int row, int numberCoefficents , 
					  int numberColumns,
					  const int * column, const double * coefficient)
  : ClpConstraint()
{
  type_=0;
  rowNumber_=row;
  numberColumns_ = numberColumns;
  numberCoefficients_=numberCoefficents;
  column_ = CoinCopyOfArray(column,numberCoefficients_);
  coefficient_ = CoinCopyOfArray(coefficient,numberCoefficients_);
  CoinSort_2(column_,column_+numberCoefficients_,coefficient_);
}

//-------------------------------------------------------------------
// Copy constructor 
//-------------------------------------------------------------------
ClpConstraintLinear::ClpConstraintLinear (const ClpConstraintLinear & rhs)
: ClpConstraint(rhs)
{  
  numberColumns_=rhs.numberColumns_;
  numberCoefficients_=rhs.numberCoefficients_;
  column_ = CoinCopyOfArray(rhs.column_,numberCoefficients_);
  coefficient_ = CoinCopyOfArray(rhs.coefficient_,numberCoefficients_);
}
  

//-------------------------------------------------------------------
// Destructor 
//-------------------------------------------------------------------
ClpConstraintLinear::~ClpConstraintLinear ()
{
  delete [] column_;
  delete [] coefficient_;
}

//----------------------------------------------------------------
// Assignment operator 
//-------------------------------------------------------------------
ClpConstraintLinear &
ClpConstraintLinear::operator=(const ClpConstraintLinear& rhs)
{
  if (this != &rhs) {
    delete [] column_;
    delete [] coefficient_;
    numberColumns_=rhs.numberColumns_;
    numberCoefficients_=rhs.numberCoefficients_;
    column_ = CoinCopyOfArray(rhs.column_,numberCoefficients_);
    coefficient_ = CoinCopyOfArray(rhs.coefficient_,numberCoefficients_);
  }
  return *this;
}
//-------------------------------------------------------------------
// Clone
//-------------------------------------------------------------------
ClpConstraint * ClpConstraintLinear::clone() const
{
  return new ClpConstraintLinear(*this);
}

// Returns gradient
int  
ClpConstraintLinear::gradient(const ClpSimplex * model,
			      const double * solution, 
			      double * gradient,
			      double & functionValue, 
			      double & offset,
			      bool useScaling,
			      bool refresh) const
{
  if (refresh||!lastGradient_) {
    functionValue_=0.0;
    if (!lastGradient_)
      lastGradient_ = new double[numberColumns_];
    CoinZeroN(lastGradient_,numberColumns_);
    bool scaling=(model&&model->rowScale()&&useScaling);
    if (!scaling) {
      for (int i=0;i<numberCoefficients_;i++) {
	int iColumn = column_[i];
	double value = solution[iColumn];
	double coefficient = coefficient_[i];
	functionValue_ += value*coefficient;
	lastGradient_[iColumn]=coefficient;
      }
    } else {
      // do scaling
      const double * columnScale = model->columnScale();
      for (int i=0;i<numberCoefficients_;i++) {
	int iColumn = column_[i];
	double value = solution[iColumn]; // already scaled
	double coefficient = coefficient_[i]*columnScale[iColumn];
	functionValue_ += value*coefficient;
	lastGradient_[iColumn]=coefficient;
      }
    }
  }
  functionValue = functionValue_;
  offset=0.0;
  CoinMemcpyN(lastGradient_,numberColumns_,gradient);
  return 0;
}
// Resize constraint
void 
ClpConstraintLinear::resize(int newNumberColumns)
{
  if (numberColumns_!=newNumberColumns) {
#ifndef NDEBUG
    int lastColumn = column_[numberCoefficients_-1];
#endif
    assert (newNumberColumns>lastColumn);
    delete [] lastGradient_;
    lastGradient_ = NULL;
    numberColumns_ = newNumberColumns;
  } 
}
// Delete columns in  constraint
void 
ClpConstraintLinear::deleteSome(int numberToDelete, const int * which) 
{
  if (numberToDelete) {
    int i ;
    char * deleted = new char[numberColumns_];
    memset(deleted,0,numberColumns_*sizeof(char));
    for (i=0;i<numberToDelete;i++) {
      int j = which[i];
      if (j>=0&&j<numberColumns_&&!deleted[j]) {
	deleted[j]=1;
      }
    }
    int n=0;
    for (i=0;i<numberCoefficients_;i++) {
      int iColumn = column_[i];
      if (!deleted[iColumn]) {
	column_[n]=iColumn;
	coefficient_[n++]=coefficient_[i];
      }
    }
    numberCoefficients_ = n;
  }
}
// Scale constraint 
void 
ClpConstraintLinear::reallyScale(const double * columnScale) 
{
  for (int i=0;i<numberCoefficients_;i++) {
    int iColumn = column_[i];
    coefficient_[i] *= columnScale[iColumn];
  }
}
/* Given a zeroed array sets nonlinear columns to 1.
   Returns number of nonlinear columns
*/
int 
ClpConstraintLinear::markNonlinear(char *) const
{
  return 0;
}
/* Given a zeroed array sets possible nonzero coefficients to 1.
   Returns number of nonzeros
*/
int 
ClpConstraintLinear::markNonzero(char * which) const
{
  for (int i=0;i<numberCoefficients_;i++) {
    int iColumn = column_[i];
    which[iColumn]=1;
  }
  return numberCoefficients_;
}
// Number of coefficients
int 
ClpConstraintLinear::numberCoefficients() const
{
  return numberCoefficients_;
}
