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/********************* */
/*! \file tableau.h
** \verbatim
** Original author: taking
** Major contributors: mdeters
** Minor contributors (to current version): dejan
** This file is part of the CVC4 prototype.
** Copyright (c) 2009, 2010 The Analysis of Computer Systems Group (ACSys)
** Courant Institute of Mathematical Sciences
** New York University
** See the file COPYING in the top-level source directory for licensing
** information.\endverbatim
**
** \brief [[ Add one-line brief description here ]]
**
** [[ Add lengthier description here ]]
** \todo document this file
**/
#include "expr/node.h"
#include "expr/attribute.h"
#include "theory/arith/arith_utilities.h"
#include "theory/arith/arithvar_set.h"
#include "theory/arith/normal_form.h"
#include "theory/arith/row_vector.h"
#include <ext/hash_map>
#include <set>
#ifndef __CVC4__THEORY__ARITH__TABLEAU_H
#define __CVC4__THEORY__ARITH__TABLEAU_H
namespace CVC4 {
namespace theory {
namespace arith {
typedef PermissiveBackArithVarSet Column;
typedef std::vector<Column> ColumnMatrix;
class Tableau {
private:
typedef std::vector< ReducedRowVector* > RowsTable;
RowsTable d_rowsTable;
ArithVarSet d_basicVariables;
std::vector<uint32_t> d_rowCount;
ColumnMatrix d_columnMatrix;
public:
/**
* Constructs an empty tableau.
*/
Tableau() :
d_rowsTable(),
d_basicVariables(),
d_rowCount(),
d_columnMatrix()
{}
/** Copy constructor. */
Tableau(const Tableau& tab);
~Tableau();
Tableau& operator=(const Tableau& tab);
size_t getNumRows() const {
return d_basicVariables.size();
}
void increaseSize(){
d_basicVariables.increaseSize();
d_rowsTable.push_back(NULL);
d_rowCount.push_back(0);
d_columnMatrix.push_back(PermissiveBackArithVarSet());
//TODO replace with version of ArithVarSet that handles misses as non-entries
// not as buffer overflows
// ColumnMatrix::iterator i = d_columnMatrix.begin(), end = d_columnMatrix.end();
// for(; i != end; ++i){
// Column& col = *i;
// col.increaseSize(d_columnMatrix.size());
// }
}
bool isBasic(ArithVar v) const {
return d_basicVariables.isMember(v);
}
ArithVarSet::iterator begin(){
return d_basicVariables.begin();
}
ArithVarSet::iterator end(){
return d_basicVariables.end();
}
const Column& getColumn(ArithVar v){
Assert(v < d_columnMatrix.size());
return d_columnMatrix[v];
}
Column::iterator beginColumn(ArithVar v){
return getColumn(v).begin();
}
Column::iterator endColumn(ArithVar v){
return getColumn(v).end();
}
ReducedRowVector& lookup(ArithVar var){
Assert(d_basicVariables.isMember(var));
Assert(d_rowsTable[var] != NULL);
return *(d_rowsTable[var]);
}
uint32_t getRowCount(ArithVar x){
Assert(x < d_rowCount.size());
AlwaysAssert(d_rowCount[x] == getColumn(x).size());
return d_rowCount[x];
}
/**
* Adds a row to the tableau.
* The new row is equivalent to:
* basicVar = \sum_i coeffs[i] * variables[i]
* preconditions:
* basicVar is already declared to be basic
* basicVar does not have a row associated with it in the tableau.
*
* Note: each variables[i] does not have to be non-basic.
* Pivoting will be mimicked if it is basic.
*/
void addRow(ArithVar basicVar,
const std::vector<Rational>& coeffs,
const std::vector<ArithVar>& variables);
/**
* preconditions:
* x_r is basic,
* x_s is non-basic, and
* a_rs != 0.
*/
void pivot(ArithVar x_r, ArithVar x_s);
void printTableau();
ReducedRowVector* removeRow(ArithVar basic);
private:
/** Copies the datastructures in tab to this.*/
void internalCopy(const Tableau& tab);
/** Clears the structures in the tableau. */
void clear();
};
}; /* namespace arith */
}; /* namespace theory */
}; /* namespace CVC4 */
#endif /* __CVC4__THEORY__ARITH__TABLEAU_H */
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