forkjo/vendor/github.com/petar/GoLLRB/llrb/llrb-stats.go

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// Copyright 2010 Petar Maymounkov. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package llrb
// GetHeight() returns an item in the tree with key @key, and it's height in the tree
func (t *LLRB) GetHeight(key Item) (result Item, depth int) {
return t.getHeight(t.root, key)
}
func (t *LLRB) getHeight(h *Node, item Item) (Item, int) {
if h == nil {
return nil, 0
}
if less(item, h.Item) {
result, depth := t.getHeight(h.Left, item)
return result, depth + 1
}
if less(h.Item, item) {
result, depth := t.getHeight(h.Right, item)
return result, depth + 1
}
return h.Item, 0
}
// HeightStats() returns the average and standard deviation of the height
// of elements in the tree
func (t *LLRB) HeightStats() (avg, stddev float64) {
av := &avgVar{}
heightStats(t.root, 0, av)
return av.GetAvg(), av.GetStdDev()
}
func heightStats(h *Node, d int, av *avgVar) {
if h == nil {
return
}
av.Add(float64(d))
if h.Left != nil {
heightStats(h.Left, d+1, av)
}
if h.Right != nil {
heightStats(h.Right, d+1, av)
}
}