ai.search
Class Node

java.lang.Object
  ai.search.Node

public class Node

extends java.lang.Object

A node in a search problem.

Author:

Jill Zimmerman -- jill.zimmerman@goucher.edu

Field Summary

java.lang.Object	action The domain action leading to the state.
int	depth The depth of the node in the tree (root = 0).
int	fCost gCost + hCost.
int	gCost The path cost from root to node.
int	hCost Estimated distance from state to goal.
Node	parent The parent Node.
java.lang.Object	state A state in the domain.
java.util.Vector	successors A list of successor Nodes.

Method Summary

java.util.Vector	expand(Problem problem) Generate a list of all the nodes that can be reached from a node.
java.util.Vector	solutionActions() Generate a list of actions that reach a solution.
java.util.Vector	solutionNodes() Generate a list of nodes that reach a solution.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

state

public java.lang.Object state

A state in the domain.

parent

public Node parent

The parent Node.

action

public java.lang.Object action

The domain action leading to the state.

successors

public java.util.Vector successors

A list of successor Nodes.

depth

public int depth

The depth of the node in the tree (root = 0).

gCost

public int gCost

The path cost from root to node.

hCost

public int hCost

Estimated distance from state to goal.

fCost

public int fCost

gCost + hCost.

Method Detail

expand

public java.util.Vector expand(Problem problem)

Generate a list of all the nodes that can be reached from a node. Note: the problem's successor method returns a list of (action . state) pairs. This function turns each of these into a node.

Parameters:

problem - is a search problem

Returns:

the list of nodes that can be reached from this node.

solutionActions

public java.util.Vector solutionActions()

Generate a list of actions that reach a solution.

Returns:

the list of actions that reach a solution.

solutionNodes

public java.util.Vector solutionNodes()

Generate a list of nodes that reach a solution.

Returns:

the list of nodes that reach a solution.