52 lines
1.1 KiB
Java
52 lines
1.1 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 PathFinder class implemented with DFS
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*
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* @author Ziver
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*/
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public class DepthFirstSearch {
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private HashSet<PathNode> visited = new HashSet<PathNode>();
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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 Start Node
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* @param stop Stop 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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visited.clear();
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PathNode node = dfs(start, stop);
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return node.traversTo( start );
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}
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/**
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* The DepthFirstSearch algorithm
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* @param node The node to search from
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* @return The stop PathNode if a path was found else null
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*/
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private PathNode dfs(PathNode node, PathNode stop){
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visited.add( node );
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if(node.equals(stop)){
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return node;
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}
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for(PathNode next : node.getNeighbors()){
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if(!visited.contains( next ) && node.getNeighborCost(next) > 0){
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next.setParentNeighbor(node);
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PathNode tmp = dfs(next, stop);
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if(tmp != null){
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return tmp;
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}
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}
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}
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return null;
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}
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}
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