/*

* Copyright 2017 Marc Liberatore.

* Modified 2018 David Wemhoener.

*/

package search;

import java.util.Set;

import java.util.List;

/**

* An implementation of a Searcher that performs an iterative search,

* storing the list of next states in a Queue. This results in a

* breadth-first search.

*

* @author liberato

*

* @param the type for each vertex in the search graph

*/

public class Searcher {

private final SearchProblem searchProblem;

/**

* Instantiates a searcher.

*

* @param searchProblem

* the search problem for which this searcher will find and

* validate solutions

*/

public Searcher(SearchProblem searchProblem) {

this.searchProblem = searchProblem;

}

/**

* Finds and return a solution to the problem, consisting of a list of

* states.

*

* The list should start with the initial state of the underlying problem.

* Then, it should have one or more additional states. Each state should be

* a successor of its predecessor. The last state should be a goal state of

* the underlying problem.

*

* If there is no solution, then this method should return an empty list.

*

* @return a solution to the problem (or an empty list)

*/

public List findSolution() {

// TODO

return null;

}

/**

* Determines what states are reachable from the start state in a

* certain number of moves

*

* @param m the number of moves from the start state

* @return a set of nodes

*/

public Set findReachableSet(int m) {

// TODO

return null;

}

/**

* Checks that a solution is valid.

*

* A valid solution consists of a list of states. The list should start with

* the initial state of the underlying problem. Then, it should have one or

* more additional states. Each state should be a successor of its

* predecessor. The last state should be a goal state of the underlying

* problem.

*

* @param solution

* @return true iff this solution is a valid solution

* @throws NullPointerException

* if solution is null

*/

public final boolean isValidSolution(List solution) {

// TODO

return false;

}

}

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