From 246ebd57055650ee9bd07d0e5b5cc8469344ba6e Mon Sep 17 00:00:00 2001
From: Schankula Christopher <schankuc@mcmaster.ca>
Date: Wed, 28 Mar 2018 09:46:54 -0400
Subject: [PATCH] use quickselect for KDT (failing...)
---
src/sort/KDT.java | 2 +-
src/sort/QuickSelect.java | 10 ++++++++++
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/src/sort/KDT.java b/src/sort/KDT.java
index cb6b9bc..681deb7 100644
--- a/src/sort/KDT.java
+++ b/src/sort/KDT.java
@@ -119,7 +119,7 @@ public class KDT<KeyVal extends Comparable<KeyVal>> implements Serializable {
int axis = depth % getK();
int mid = (lo + hi) / 2;
- MergeSort.sort(keyvals, lo, hi, axes.get(axis));
+ QuickSelect.median(keyvals, lo, hi, axes.get(axis));
KeyVal median = (KeyVal) keyvals[mid];
//TODO: fix size
diff --git a/src/sort/QuickSelect.java b/src/sort/QuickSelect.java
index 6233522..1b7e0e3 100644
--- a/src/sort/QuickSelect.java
+++ b/src/sort/QuickSelect.java
@@ -30,6 +30,16 @@ public class QuickSelect {
sort(a, 0, a.length - 1, a.length/2, gc);
}
+ /**
+ * Partially sorts a comparable array such that elements smaller than the median occur in
+ * the first half of the array, and elements larger than the median occur in the second half
+ * @param a Array of comparable items
+ * @param gc Lambda function to compare items
+ */
+ public static <T> void median(Comparable<T>[] a, int lo, int hi, GeneralCompare<T> gc) {
+ sort(a, lo, hi, (hi - lo) / 2, gc);
+ }
+
/**
* Partially sorts a comparable array such that elements smaller than the kth largest element
* occur in the first half of the array, and larger elements occur in the second half
--
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