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something like a huffman trie

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This commit is contained in:
Vincent Batts 2014-04-13 10:33:41 -04:00
parent 3dfc7e093f
commit 2d48a86f5e
1 changed files with 26 additions and 13 deletions
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39
huffman.go
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@ -16,16 +16,22 @@ func (n Node) Lookup(value interface{}) *Node {
}
func NewPathTree(paths []string) *Node {
nodes := []Node{}
nodes := []*Node{}
for i := range paths {
node := Node{Weight: int64(i + 1), Value: paths[i]}
nodes = append(nodes, node)
nodes = append(nodes, &Node{Weight: int64(i + 1), Value: paths[i]})
}
nodeHeap := nodeInterface(nodes)
heap.Init(nodeHeap)
return &Node{}
h := nodeInterface(nodes)
h_ptr := &h
heap.Init(h_ptr)
count := h_ptr.Len()
for count > 1 {
left := heap.Pop(h_ptr)
right := heap.Pop(h_ptr)
heap.Push(h_ptr, Combine(left.(*Node), right.(*Node)))
count = h_ptr.Len()
}
return heap.Pop(h_ptr).(*Node)
}
func Combine(left *Node, right *Node) *Node {
@ -43,10 +49,17 @@ func Combine(left *Node, right *Node) *Node {
}
}
type nodeInterface []Node
type nodeInterface []*Node
func (ni nodeInterface) Push(x interface{}) {}
func (ni nodeInterface) Pop() interface{} { return Node{} }
func (ni nodeInterface) Len() int { return len(ni) }
func (ni nodeInterface) Less(i, j int) bool { return ni[i].Weight < ni[j].Weight }
func (ni nodeInterface) Swap(i, j int) { ni[i], ni[j] = ni[j], ni[i] }
func (ni nodeInterface) Len() int { return len(ni) }
func (ni nodeInterface) Less(i, j int) bool { return ni[i].Weight < ni[j].Weight }
func (ni nodeInterface) Swap(i, j int) { ni[i], ni[j] = ni[j], ni[i] }
func (ni *nodeInterface) Push(x interface{}) { *ni = append(*ni, x.(*Node)) }
func (ni *nodeInterface) Pop() interface{} {
old := *ni
n := len(old)
x := old[n-1]
*ni = old[0 : n-1]
return x
}