From: Russ Cox <rsc@golang.org>
Date: Wed, 16 Sep 2009 17:43:49 +0000 (-0700)
Subject: add heap.Remove
X-Git-Tag: weekly.2009-11-06~565
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=0ee18ca8169b6dcbc527627bb803b0ddcbee06f6;p=gostls13.git

add heap.Remove

R=gri
DELTA=14  (14 added, 0 deleted, 0 changed)
OCL=34636
CL=34687
---

diff --git a/src/pkg/container/heap/heap.go b/src/pkg/container/heap/heap.go
index d35f4d1335..6e7eccb5f2 100644
--- a/src/pkg/container/heap/heap.go
+++ b/src/pkg/container/heap/heap.go
@@ -52,6 +52,20 @@ func Pop(h HeapInterface) interface{} {
 }
 
 
+// Remove removes the element at index i from the heap.
+// The complexity is O(log(n)) where n = h.Len().
+//
+func Remove(h HeapInterface, i int) interface{} {
+	n := h.Len()-1;
+	if n != i {
+		h.Swap(n, i);
+		down(h, i, n);
+		up(h, i);
+	}
+	return h.Pop();
+}
+
+
 func up(h HeapInterface, j int) {
 	for {
 		i := (j-1)/2;