From c8715e3dbba33134d4b081ac3c389b5c6526609a Mon Sep 17 00:00:00 2001
From: Harrison <yunyangdeng@gmail.com>
Date: Wed, 22 Apr 2020 17:50:19 -0500
Subject: [PATCH] DFS target finding will now prioritize user given end node.

Meaning if the general area of the target is known, DFS can use it.
---
 .../islandsurvivalcraft/pathfinding/DepthFirstSearch.java | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/main/java/ca/recrown/islandsurvivalcraft/pathfinding/DepthFirstSearch.java b/src/main/java/ca/recrown/islandsurvivalcraft/pathfinding/DepthFirstSearch.java
index 2433db2..29d132d 100644
--- a/src/main/java/ca/recrown/islandsurvivalcraft/pathfinding/DepthFirstSearch.java
+++ b/src/main/java/ca/recrown/islandsurvivalcraft/pathfinding/DepthFirstSearch.java
@@ -1,7 +1,6 @@
 package ca.recrown.islandsurvivalcraft.pathfinding;
 
 import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.Objects;
 import java.util.PriorityQueue;
 import java.util.Queue;
@@ -17,6 +16,7 @@ public class DepthFirstSearch {
 
     public DepthFirstSearch() {
         checkedNodes = new HashSet<>();
+        queue = new PriorityQueue<>();
     }
 
     public DepthFirstSearch(CoordinateValidatable validatable) {
@@ -53,7 +53,7 @@ public class DepthFirstSearch {
         if (validatable == null) throw new IllegalStateException("Need to set a validator.");
         if (startNode == null) throw new IllegalStateException("Need to set the starting position.");
 
-        queue = new PriorityQueue<>();
+        queue.clear();
         checkedNodes.clear();
         Node begin = startNode;
         queue.add(begin);
@@ -82,6 +82,7 @@ public class DepthFirstSearch {
 
     /**
      * Finds the end node.
+     * If an end node is set, it will try going in that direction first.
      * Will not set end node if one wasn't found,
      * therefore, previous end node data is kept.
      * @param targetValidator
@@ -92,7 +93,7 @@ public class DepthFirstSearch {
         if (targetValidator == null) throw new NullArgumentException("targetValidator");
         if (startNode == null) throw new IllegalStateException("Need to set the starting position.");
 
-        queue = new LinkedList<>();
+        queue.clear();
         checkedNodes.clear();
         Node begin = startNode;
         queue.add(begin);
@@ -134,6 +135,7 @@ public class DepthFirstSearch {
 
         @Override
         public int compareTo(Node o) {
+            if (endNode == null) return 0;
             return Math.round(distanceToGoal(endNode) - o.distanceToGoal(endNode));
         }