operations_research::KnapsackSearchPath Class Reference

Detailed Description

KnapsackSearchPath is a small class used to represent the path between a node to another node in the search tree.

As the solution state is not stored for each search node, the state should be rebuilt at each node. One simple solution is to apply all decisions between the node 'to' and the root. This can be computed in O(number_of_items). However, it is possible to achieve better average complexity. Two consecutively explored nodes are usually close enough (i.e., much less than number_of_items) to benefit from an incremental update from the node 'from' to the node 'to'. The 'via' field is the common parent of 'from' field and 'to' field. So the state can be built by reverting all decisions from 'from' to 'via' and then applying all decisions from 'via' to 'to'.

Definition at line 379 of file knapsack_solver.h.

#include <knapsack_solver.h>

Public Member Functions
	KnapsackSearchPath (const KnapsackSearchNode &from, const KnapsackSearchNode &to)
	KnapsackSearchPath (const KnapsackSearchPath &)=delete
KnapsackSearchPath &	operator= (const KnapsackSearchPath &)=delete
void	Init ()
const KnapsackSearchNode &	from () const
const KnapsackSearchNode &	via () const
const KnapsackSearchNode &	to () const
const KnapsackSearchNode *	MoveUpToDepth (const KnapsackSearchNode &node, int depth) const

Constructor & Destructor Documentation

KnapsackSearchPath() [1/2]

operations_research::KnapsackSearchPath::KnapsackSearchPath	(	const KnapsackSearchNode &	from,
		const KnapsackSearchNode &	to )

Definition at line 121 of file knapsack_solver.cc.

KnapsackSearchPath() [2/2]

operations_research::KnapsackSearchPath::KnapsackSearchPath ( const KnapsackSearchPath & )

delete

Member Function Documentation

from()

const KnapsackSearchNode & operations_research::KnapsackSearchPath::from ( ) const

inline

Definition at line 391 of file knapsack_solver.h.

Init()

void operations_research::KnapsackSearchPath::Init

(

)

Definition at line 125 of file knapsack_solver.cc.

MoveUpToDepth()

const KnapsackSearchNode * operations_research::KnapsackSearchPath::MoveUpToDepth	(	const KnapsackSearchNode &	node,
		int	depth ) const

Definition at line 138 of file knapsack_solver.cc.

operator=()

KnapsackSearchPath & operations_research::KnapsackSearchPath::operator= ( const KnapsackSearchPath & )

delete

to()

const KnapsackSearchNode & operations_research::KnapsackSearchPath::to ( ) const

inline

Definition at line 393 of file knapsack_solver.h.

via()

const KnapsackSearchNode & operations_research::KnapsackSearchPath::via ( ) const

inline

Definition at line 392 of file knapsack_solver.h.

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The documentation for this class was generated from the following files:

• ortools/algorithms/knapsack_solver.h
• ortools/algorithms/knapsack_solver.cc