From 21491b20cfb4fa3c346a1f1754acdd5dc4d5aa4a Mon Sep 17 00:00:00 2001
From: Schankula Christopher <schankuc@mcmaster.ca>
Date: Sun, 4 Mar 2018 15:47:47 -0500
Subject: [PATCH] very first minimally working (for building) KD tree, search
next
---
src/sandbox/Point.java | 29 +++++++++++++
src/sort/KDT.java | 90 +++++++++++++++++++++++++++++++++++++++++
src/sort/MergeSort.java | 2 +-
3 files changed, 120 insertions(+), 1 deletion(-)
create mode 100644 src/sandbox/Point.java
create mode 100644 src/sort/KDT.java
diff --git a/src/sandbox/Point.java b/src/sandbox/Point.java
new file mode 100644
index 0000000..0fa4f16
--- /dev/null
+++ b/src/sandbox/Point.java
@@ -0,0 +1,29 @@
+package sandbox;
+
+public class Point implements Comparable<Point> {
+ private final int x;
+ private final int y;
+
+ public Point(int x, int y) {
+ this.x = x;
+ this.y = y;
+ }
+
+ public int getX() {
+ return this.x;
+ }
+
+ public int getY() {
+ return this.y;
+ }
+
+ public String toString() {
+ return String.format("(%d,%d)", x, y);
+ }
+
+ @Override
+ public int compareTo(Point o) {
+ // TODO Auto-generated method stub
+ return 0;
+ }
+}
diff --git a/src/sort/KDT.java b/src/sort/KDT.java
new file mode 100644
index 0000000..5d18b3d
--- /dev/null
+++ b/src/sort/KDT.java
@@ -0,0 +1,90 @@
+package sort;
+
+import sandbox.Point;
+import java.util.ArrayList;
+
+public class KDT<KeyVal extends Comparable<KeyVal>> {
+ Node root;
+ ArrayList<GeneralCompare<KeyVal>> axes;
+
+ public static void main(String[] args) {
+ GeneralCompare<Point> compX = (p1, p2) -> ((Point) p1).getX() - ((Point) p2).getX();
+ GeneralCompare<Point> compY = (p1, p2) -> ((Point) p1).getY() - ((Point) p2).getY();
+
+ //(2,3), (4,7), (5,4), (7,2), (8,1), (9,6)
+ //(8,1), (7,2), (2,3), (5,4), (9,6), (4,7)
+ Point p1 = new Point(2,3);
+ Point p2 = new Point(5,4);
+ Point p3 = new Point(9,6);
+ Point p4 = new Point(4,7);
+ Point p5 = new Point(8,1);
+ Point p6 = new Point(7,2);
+
+ ArrayList<GeneralCompare<Point>> axes = new ArrayList<GeneralCompare<Point>>();
+ axes.add(compX);
+ axes.add(compY);
+
+ Point[] pts = {p1, p2, p3, p4, p5, p6};
+
+ KDT<Point> kdt = new KDT(axes, pts);
+ System.out.println(kdt.size());
+ System.out.println(kdt.height());
+ }
+
+ private class Node{
+ private KeyVal keyval;
+ private Node left, right;
+ private int n;
+
+ public Node(KeyVal keyval, int n) {
+ this.keyval = keyval;
+ this.n = n;
+ }
+ }
+
+ public KDT(ArrayList<GeneralCompare<KeyVal>> axes, Comparable<KeyVal>[] keyvals) {
+ this.axes = axes;
+ root = buildTree(keyvals, 0, keyvals.length - 1, 0);
+ }
+
+ private Node buildTree(Comparable<KeyVal>[] keyvals, int lo, int hi, int depth) {
+ if (lo > hi) return null;
+ int axis = depth % getK();
+
+ int mid = (lo + hi) / 2;
+ MergeSort.sort(keyvals, lo, hi, axes.get(axis));
+ KeyVal median = (KeyVal) keyvals[mid];
+
+ System.out.println(median);
+
+ //TODO: fix size
+ Node newNode = new Node(median, 0);
+ newNode.left = buildTree(keyvals, lo, mid - 1, depth + 1);
+ newNode.right = buildTree(keyvals, mid + 1, hi, depth + 1);
+
+ newNode.n = size(newNode.left) + size(newNode.right) + 1;
+ return newNode;
+ }
+
+ public int size() {
+ return size(root);
+ }
+
+ public int height() {
+ return height(root);
+ }
+
+ private int height(Node x) {
+ if (x == null) return 0;
+ return 1 + Math.max(height(x.left), height(x.right));
+ }
+
+ private int size(Node x) {
+ if (x == null) return 0;
+ else return x.n;
+ }
+
+ public int getK() {
+ return axes.size();
+ }
+}
diff --git a/src/sort/MergeSort.java b/src/sort/MergeSort.java
index 7f80c52..defaccf 100644
--- a/src/sort/MergeSort.java
+++ b/src/sort/MergeSort.java
@@ -37,7 +37,7 @@ public class MergeSort{
int mid = lo + (n/2);
// Fill auxiliary array
- System.out.println("lo, mid, hi: " + lo + ", " + mid + ", " + hi);
+ //System.out.println("lo, mid, hi: " + lo + ", " + mid + ", " + hi);
for(int k = lo; k <= hi; k++){
aux[k] = x[k];
--
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