48 lines
1 KiB
Java
48 lines
1 KiB
Java
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package zutil.algo.path;
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import java.util.HashSet;
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import java.util.LinkedList;
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import java.util.Queue;
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/**
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* A class that uses BFS to find a path
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*
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* @author Ziver
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*/
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public class BreadthFirstSearch implements PathFinder{
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/**
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* Returns the first path to the destination
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*
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* @param start is the start Node
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* @param stop is the goal Node
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* @return A list with the path
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*/
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public LinkedList<PathNode> find(PathNode start, PathNode stop){
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Queue<PathNode> queue = new LinkedList<PathNode>();
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HashSet<PathNode> visited = new HashSet<PathNode>();
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queue.add(start);
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visited.add( start );
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PathNode tmp;
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while(!queue.isEmpty()){
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tmp = queue.poll();
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for(PathNode next : tmp.getNeighbors()){
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if(!visited.contains( next ) && tmp.getNeighborCost(next) > 0){
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queue.add(next);
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visited.add( next );
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next.setParentNeighbor(tmp);
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if(next.equals(stop)){
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return stop.traversTo(start);
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}
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}
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}
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}
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return new LinkedList<PathNode>();
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}
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}
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