Detailed Description

Simple class to combine linear expression efficiently. First in a sparse way that switch to dense when the number of non-zeros grows.

Definition at line 60 of file linear_programming_constraint.h.

#include <linear_programming_constraint.h>

Public Member Functions
void	ClearAndResize (int size)
bool	Add (glop::ColIndex col, IntegerValue value)
	Does vector[col] += value and return false in case of overflow.
template<bool check_overflow = true>
bool	AddLinearExpressionMultiple (IntegerValue multiplier, absl::Span< const glop::ColIndex > cols, absl::Span< const IntegerValue > coeffs, IntegerValue max_coeff_magnitude)
	Force instantations for tests.
LinearConstraint	ConvertToLinearConstraint (absl::Span< const IntegerVariable > integer_variables, IntegerValue upper_bound, std::optional< std::pair< IntegerVariable, IntegerValue > > extra_term=std::nullopt)
void	ConvertToCutData (absl::int128 rhs, absl::Span< const IntegerVariable > integer_variables, absl::Span< const double > lp_solution, IntegerTrail integer_trail, CutData result)
std::vector< std::pair< glop::ColIndex, IntegerValue > >	GetTerms ()
	Similar to ConvertToLinearConstraint().
IntegerValue	operator[] (glop::ColIndex col) const
	We only provide the const [].
bool	IsSparse () const

Member Function Documentation

◆ Add()

bool operations_research::sat::ScatteredIntegerVector::Add	(	glop::ColIndex	col,
		IntegerValue	value )

Does vector[col] += value and return false in case of overflow.

Definition at line 98 of file linear_programming_constraint.cc.

◆ AddLinearExpressionMultiple()

template<bool check_overflow>

template bool operations_research::sat::ScatteredIntegerVector::AddLinearExpressionMultiple< false >	(	IntegerValue	multiplier,
		absl::Span< const glop::ColIndex >	cols,
		absl::Span< const IntegerValue >	coeffs,
		IntegerValue	max_coeff_magnitude )

Force instantations for tests.

Similar to Add() but for multiplier * terms.

Returns false if we encountered any integer overflow. If the template bool is false, we do not check for a bit of extra speed.

Since we have the norm, this avoid checking each products below.

Definition at line 112 of file linear_programming_constraint.cc.

◆ ClearAndResize()

void operations_research::sat::ScatteredIntegerVector::ClearAndResize ( int size )

This must be called with the correct size before any other functions are used.

Definition at line 81 of file linear_programming_constraint.cc.

◆ ConvertToCutData()

void operations_research::sat::ScatteredIntegerVector::ConvertToCutData	(	absl::int128	rhs,
		absl::Span< const IntegerVariable >	integer_variables,
		absl::Span< const double >	lp_solution,
		IntegerTrail *	integer_trail,
		CutData *	result )

Definition at line 230 of file linear_programming_constraint.cc.

◆ ConvertToLinearConstraint()

LinearConstraint operations_research::sat::ScatteredIntegerVector::ConvertToLinearConstraint	(	absl::Span< const IntegerVariable >	integer_variables,
		IntegerValue	upper_bound,
		std::optional< std::pair< IntegerVariable, IntegerValue > >	extra_term = std::nullopt )

This is not const only because non_zeros is sorted. Note that sorting the non-zeros make the result deterministic whether or not we were in sparse mode.