From de3b3a614ae2f15be24b036335afc0910e411edf Mon Sep 17 00:00:00 2001
From: Harrison <yunyangdeng@gmail.com>
Date: Thu, 23 Apr 2020 21:16:43 -0500
Subject: [PATCH] Changed DFS order of operation.

---
 .../pathfinding/DepthFirstSearch.java         | 55 +++++--------------
 1 file changed, 13 insertions(+), 42 deletions(-)

diff --git a/src/main/java/ca/recrown/islandsurvivalcraft/pathfinding/DepthFirstSearch.java b/src/main/java/ca/recrown/islandsurvivalcraft/pathfinding/DepthFirstSearch.java
index a0d0e01..6ad18f3 100644
--- a/src/main/java/ca/recrown/islandsurvivalcraft/pathfinding/DepthFirstSearch.java
+++ b/src/main/java/ca/recrown/islandsurvivalcraft/pathfinding/DepthFirstSearch.java
@@ -66,32 +66,13 @@ public class DepthFirstSearch {
         if (coordValidatable == null) throw new IllegalStateException("Need to set a validator.");
         if (startNode == null) throw new IllegalStateException("Need to set the starting position.");
 
-        queue.clear();
-        checkedNodes.clear();
-        Node begin = startNode;
-        queue.add(begin);
-        while (!queue.isEmpty()) {
-            if (maxNodesSearched != -1 && checkedNodes.size() > maxNodesSearched) return false;
-            Node n = queue.poll();
-            if (!n.equals(endNode)) {
-                n.child[0] = new Node(n, n.x + 1, n.y);
-                n.child[1] = new Node(n, n.x - 1, n.y);
-                n.child[2] = new Node(n, n.x, n.y + 1);
-                n.child[3] = new Node(n, n.x, n.y - 1);
-            } else {
-                n.shallowCopyTo(endNode);
-                return true;
+        return findTarget(new CoordinateTargetValidatable() {
+        
+            @Override
+            public boolean isCoordinateTarget(int x, int y) {
+                return endNode.x == x && endNode.y == y;
             }
-            if (checkedNodes.add(n)) {
-                for (int i = 0; i < n.child.length; i++) {
-                    Node child = n.child[i];
-                    if (coordValidatable.validate(child.x, child.y)) {
-                        queue.add(child);
-                    }
-                }
-            }
-        }
-        return false;
+        });
     }
 
     /**
@@ -114,22 +95,19 @@ public class DepthFirstSearch {
         while (!queue.isEmpty()) {
             Node n = queue.poll();
             if (maxNodesSearched != -1 && checkedNodes.size() > maxNodesSearched) return false;
-            if (!targetValidator.isCoordinateTarget(n.x, n.y)) {
+            if (checkedNodes.add(n) && coordValidatable.validate(n.x, n.y)) {
                 n.child[0] = new Node(n, n.x + 1, n.y);
                 n.child[1] = new Node(n, n.x - 1, n.y);
                 n.child[2] = new Node(n, n.x, n.y + 1);
                 n.child[3] = new Node(n, n.x, n.y - 1);
-            } else {
-                foundX = n.x;
-                foundY = n.y;
-                return true;
-            }
-            if (checkedNodes.add(n)) {
+                if (targetValidator.isCoordinateTarget(n.x, n.y)) {
+                    foundX = n.x;
+                    foundY = n.y;
+                    return true;
+                }
                 for (int i = 0; i < n.child.length; i++) {
                     Node child = n.child[i];
-                    if (coordValidatable.validate(child.x, child.y)) {
-                        queue.add(child);
-                    }
+                    queue.add(child);
                 }
             }
         }
@@ -181,12 +159,5 @@ public class DepthFirstSearch {
         public int hashCode() {
             return Objects.hash(x, y);
         }
-
-        public void shallowCopyTo(Node node) {
-            node.child = this.child;
-            node.parent = this.parent;
-            node.x = this.x;
-            node.y = this.y;
-        }
     }
 }
\ No newline at end of file