642 lines
12 KiB
Go
642 lines
12 KiB
Go
package avlkey
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import (
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"github.com/davecgh/go-spew/spew"
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"github.com/emirpasic/gods/utils"
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)
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type Node struct {
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children [2]*Node
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parent *Node
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height int
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key, value interface{}
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}
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// func (n *Node) String() string {
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// if n == nil {
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// return "nil"
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// }
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// return spew.Sprint(n.value)
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// }
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func (n *Node) String() string {
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if n == nil {
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return "nil"
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}
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p := "nil"
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if n.parent != nil {
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p = spew.Sprint(n.parent.value)
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}
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return spew.Sprint(n.value) + "(" + p + "|" + spew.Sprint(n.height) + ")"
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}
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type Tree struct {
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root *Node
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size int
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comparator utils.Comparator
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}
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func New(comparator utils.Comparator) *Tree {
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return &Tree{comparator: comparator}
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}
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func (avl *Tree) String() string {
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if avl.size == 0 {
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return ""
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}
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str := "AVLTree\n"
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output(avl.root, "", true, &str)
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return str
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}
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func (avl *Tree) Iterator() *Iterator {
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return initIterator(avl)
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}
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func (avl *Tree) Size() int {
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return avl.size
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}
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func (avl *Tree) Remove(key interface{}) *Node {
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if n, ok := avl.GetNode(key); ok {
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avl.size--
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if avl.size == 0 {
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avl.root = nil
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return n
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}
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left := getHeight(n.children[0])
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right := getHeight(n.children[1])
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if left == -1 && right == -1 {
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p := n.parent
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p.children[getRelationship(n)] = nil
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avl.fixRemoveHeight(p)
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return n
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}
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var cur *Node
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if left > right {
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cur = n.children[0]
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for cur.children[1] != nil {
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cur = cur.children[1]
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}
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cleft := cur.children[0]
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cur.parent.children[getRelationship(cur)] = cleft
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if cleft != nil {
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cleft.parent = cur.parent
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}
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} else {
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cur = n.children[1]
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for cur.children[0] != nil {
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cur = cur.children[0]
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}
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cright := cur.children[1]
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cur.parent.children[getRelationship(cur)] = cright
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if cright != nil {
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cright.parent = cur.parent
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}
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}
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cparent := cur.parent
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// 修改为interface 交换
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n.key, n.value, cur.key, cur.value = cur.key, cur.value, n.key, n.value
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// 考虑到刚好替换的节点是 被替换节点的孩子节点的时候, 从自身修复高度
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if cparent == n {
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avl.fixRemoveHeight(n)
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} else {
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avl.fixRemoveHeight(cparent)
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}
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return cur
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}
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return nil
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}
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func (avl *Tree) Get(key interface{}) (interface{}, bool) {
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n, ok := avl.GetNode(key)
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if ok {
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return n.value, true
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}
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return n, false
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}
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func (avl *Tree) GetAround(key interface{}) (result [3]interface{}) {
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an := avl.GetAroundNode(key)
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for i, n := range an {
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if n != nil {
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result[i] = n.value
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}
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}
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return
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}
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func (avl *Tree) GetAroundNode(key interface{}) (result [3]*Node) {
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n := avl.root
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for {
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if n == nil {
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return
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}
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lastc := 0
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switch c := avl.comparator(key, n.key); c {
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case -1:
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if c != -lastc {
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result[0] = n
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}
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lastc = c
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n = n.children[0]
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case 1:
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if c != -lastc {
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result[2] = n
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}
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lastc = c
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n = n.children[1]
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case 0:
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switch lastc {
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case -1:
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if n.children[1] != nil {
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result[0] = n.children[1]
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}
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case 1:
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if n.children[0] != nil {
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result[2] = n.children[0]
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}
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case 0:
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if n.children[1] != nil {
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result[0] = n.children[1]
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}
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if n.children[0] != nil {
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result[2] = n.children[0]
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}
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result[1] = n
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return
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}
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default:
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panic("Get comparator only is allowed in -1, 0, 1")
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}
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}
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}
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func (avl *Tree) GetNode(key interface{}) (*Node, bool) {
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for n := avl.root; n != nil; {
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switch c := avl.comparator(key, n.key); c {
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case -1:
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n = n.children[0]
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case 1:
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n = n.children[1]
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case 0:
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return n, true
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default:
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panic("Get comparator only is allowed in -1, 0, 1")
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}
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}
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return nil, false
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}
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func (avl *Tree) Put(key, value interface{}) {
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avl.size++
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node := &Node{key: key, value: value}
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if avl.size == 1 {
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avl.root = node
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return
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}
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cur := avl.root
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parent := cur.parent
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child := -1
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for {
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if cur == nil {
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parent.children[child] = node
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node.parent = parent
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if node.parent.height == 0 {
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avl.fixPutHeight(node.parent)
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}
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return
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}
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parent = cur
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c := avl.comparator(key, cur.key)
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child = (c + 2) / 2
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cur = cur.children[child]
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}
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}
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func (avl *Tree) debugString() string {
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if avl.size == 0 {
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return ""
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}
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str := "AVLTree\n"
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outputfordebug(avl.root, "", true, &str)
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return str
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}
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func (avl *Tree) TraversalBreadth() (result []interface{}) {
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result = make([]interface{}, 0, avl.size)
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var traverasl func(cur *Node)
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traverasl = func(cur *Node) {
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if cur == nil {
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return
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}
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result = append(result, cur.value)
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traverasl(cur.children[0])
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traverasl(cur.children[1])
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}
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traverasl(avl.root)
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return
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}
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func (avl *Tree) TraversalDepth(leftright int) (result []interface{}) {
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result = make([]interface{}, 0, avl.size)
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if leftright < 0 {
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var traverasl func(cur *Node)
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traverasl = func(cur *Node) {
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if cur == nil {
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return
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}
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traverasl(cur.children[0])
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result = append(result, cur.value)
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traverasl(cur.children[1])
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}
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traverasl(avl.root)
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} else {
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var traverasl func(cur *Node)
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traverasl = func(cur *Node) {
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if cur == nil {
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return
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}
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traverasl(cur.children[1])
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result = append(result, cur.value)
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traverasl(cur.children[0])
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}
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traverasl(avl.root)
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}
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return
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}
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func (avl *Tree) lrrotate(cur *Node) {
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const l = 1
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const r = 0
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movparent := cur.children[l]
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mov := movparent.children[r]
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mov.key, mov.value, cur.key, cur.value = cur.key, cur.value, mov.key, mov.value //交换值达到, 相对位移
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if mov.children[l] != nil {
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movparent.children[r] = mov.children[l]
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movparent.children[r].parent = movparent
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//movparent.children[r].child = l
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} else {
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movparent.children[r] = nil
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}
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if mov.children[r] != nil {
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mov.children[l] = mov.children[r]
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//mov.children[l].child = l
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} else {
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mov.children[l] = nil
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}
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if cur.children[r] != nil {
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mov.children[r] = cur.children[r]
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mov.children[r].parent = mov
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} else {
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mov.children[r] = nil
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}
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cur.children[r] = mov
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mov.parent = cur
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mov.height = getMaxChildrenHeight(mov) + 1
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movparent.height = getMaxChildrenHeight(movparent) + 1
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cur.height = getMaxChildrenHeight(cur) + 1
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}
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func (avl *Tree) rlrotate(cur *Node) {
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const l = 0
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const r = 1
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movparent := cur.children[l]
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mov := movparent.children[r]
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mov.key, mov.value, cur.key, cur.value = cur.key, cur.value, mov.key, mov.value //交换值达到, 相对位移
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if mov.children[l] != nil {
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movparent.children[r] = mov.children[l]
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movparent.children[r].parent = movparent
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} else {
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movparent.children[r] = nil
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}
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if mov.children[r] != nil {
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mov.children[l] = mov.children[r]
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} else {
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mov.children[l] = nil
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}
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if cur.children[r] != nil {
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mov.children[r] = cur.children[r]
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mov.children[r].parent = mov
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} else {
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mov.children[r] = nil
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}
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cur.children[r] = mov
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mov.parent = cur
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mov.height = getMaxChildrenHeight(mov) + 1
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movparent.height = getMaxChildrenHeight(movparent) + 1
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cur.height = getMaxChildrenHeight(cur) + 1
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}
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func (avl *Tree) rrotate(cur *Node) {
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const l = 0
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const r = 1
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// 1 right 0 left
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mov := cur.children[l]
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mov.key, mov.value, cur.key, cur.value = cur.key, cur.value, mov.key, mov.value //交换值达到, 相对位移
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// if mov.children[l] != nil {
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// mov.children[l].parent = cur
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// cur.children[l] = mov.children[l]
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// } else {
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// cur.children[l] = nil
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// }
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// 不可能为nil
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mov.children[l].parent = cur
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cur.children[l] = mov.children[l]
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// 解决mov节点孩子转移的问题
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if mov.children[r] != nil {
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mov.children[l] = mov.children[r]
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} else {
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mov.children[l] = nil
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}
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if cur.children[r] != nil {
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mov.children[r] = cur.children[r]
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mov.children[r].parent = mov
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} else {
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mov.children[r] = nil
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}
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// 连接转移后的节点 由于mov只是与cur交换值,parent不变
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cur.children[r] = mov
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mov.height = getMaxChildrenHeight(mov) + 1
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cur.height = getMaxChildrenHeight(cur) + 1
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}
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func (avl *Tree) lrotate(cur *Node) {
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const l = 1
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const r = 0
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mov := cur.children[l]
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mov.key, mov.value, cur.key, cur.value = cur.key, cur.value, mov.key, mov.value //交换值达到, 相对位移
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// if mov.children[l] != nil {
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// mov.children[l].parent = cur
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// cur.children[l] = mov.children[l]
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// } else {
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// cur.children[l] = nil
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// }
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// 不可能为nil
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mov.children[l].parent = cur
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cur.children[l] = mov.children[l]
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if mov.children[r] != nil {
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mov.children[l] = mov.children[r]
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} else {
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mov.children[l] = nil
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}
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if cur.children[r] != nil {
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mov.children[r] = cur.children[r]
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mov.children[r].parent = mov
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} else {
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mov.children[r] = nil
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}
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cur.children[r] = mov
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mov.height = getMaxChildrenHeight(mov) + 1
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cur.height = getMaxChildrenHeight(cur) + 1
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}
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func getMaxAndChildrenHeight(cur *Node) (h1, h2, maxh int) {
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h1 = getHeight(cur.children[0])
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h2 = getHeight(cur.children[1])
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if h1 > h2 {
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maxh = h1
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} else {
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maxh = h2
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}
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return
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}
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func getMaxChildrenHeight(cur *Node) int {
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h1 := getHeight(cur.children[0])
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h2 := getHeight(cur.children[1])
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if h1 > h2 {
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return h1
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}
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return h2
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}
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func getHeight(cur *Node) int {
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if cur == nil {
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return -1
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}
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return cur.height
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}
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func (avl *Tree) fixRemoveHeight(cur *Node) {
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for {
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lefth, rigthh, lrmax := getMaxAndChildrenHeight(cur)
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// 判断当前节点是否有变化, 如果没变化的时候, 不需要往上修复
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isBreak := false
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if cur.height == lrmax+1 {
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isBreak = true
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} else {
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cur.height = lrmax + 1
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}
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// 计算高度的差值 绝对值大于2的时候需要旋转
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diff := lefth - rigthh
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if diff < -1 {
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r := cur.children[1] // 根据左旋转的右边节点的子节点 左右高度选择旋转的方式
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if getHeight(r.children[0]) > getHeight(r.children[1]) {
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avl.lrrotate(cur)
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} else {
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avl.lrotate(cur)
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}
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} else if diff > 1 {
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l := cur.children[0]
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if getHeight(l.children[1]) > getHeight(l.children[0]) {
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avl.rlrotate(cur)
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} else {
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avl.rrotate(cur)
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}
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} else {
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if isBreak {
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return
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}
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}
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if cur.parent == nil {
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return
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}
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cur = cur.parent
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}
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}
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func (avl *Tree) fixPutHeight(cur *Node) {
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for {
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lefth := getHeight(cur.children[0])
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rigthh := getHeight(cur.children[1])
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// 计算高度的差值 绝对值大于2的时候需要旋转
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diff := lefth - rigthh
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if diff < -1 {
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r := cur.children[1] // 根据左旋转的右边节点的子节点 左右高度选择旋转的方式
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if getHeight(r.children[0]) > getHeight(r.children[1]) {
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avl.lrrotate(cur)
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} else {
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avl.lrotate(cur)
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}
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} else if diff > 1 {
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l := cur.children[0]
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if getHeight(l.children[1]) > getHeight(l.children[0]) {
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avl.rlrotate(cur)
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} else {
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avl.rrotate(cur)
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}
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} else {
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// 选择一个child的最大高度 + 1为 高度
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if lefth > rigthh {
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cur.height = lefth + 1
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} else {
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cur.height = rigthh + 1
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}
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}
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if cur.parent == nil || cur.height < cur.parent.height {
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return
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}
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cur = cur.parent
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}
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}
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func output(node *Node, prefix string, isTail bool, str *string) {
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if node.children[1] != nil {
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newPrefix := prefix
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if isTail {
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newPrefix += "│ "
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} else {
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newPrefix += " "
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}
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output(node.children[1], newPrefix, false, str)
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}
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*str += prefix
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if isTail {
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*str += "└── "
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} else {
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*str += "┌── "
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}
|
|
|
|
*str += spew.Sprint(node.value) + "\n"
|
|
|
|
if node.children[0] != nil {
|
|
newPrefix := prefix
|
|
if isTail {
|
|
newPrefix += " "
|
|
} else {
|
|
newPrefix += "│ "
|
|
}
|
|
output(node.children[0], newPrefix, true, str)
|
|
}
|
|
|
|
}
|
|
|
|
func outputfordebug(node *Node, prefix string, isTail bool, str *string) {
|
|
|
|
if node.children[1] != nil {
|
|
newPrefix := prefix
|
|
if isTail {
|
|
newPrefix += "│ "
|
|
} else {
|
|
newPrefix += " "
|
|
}
|
|
outputfordebug(node.children[1], newPrefix, false, str)
|
|
}
|
|
*str += prefix
|
|
if isTail {
|
|
*str += "└── "
|
|
} else {
|
|
*str += "┌── "
|
|
}
|
|
|
|
suffix := "("
|
|
parentv := ""
|
|
if node.parent == nil {
|
|
parentv = "nil"
|
|
} else {
|
|
parentv = spew.Sprint(node.parent.value)
|
|
}
|
|
suffix += parentv + "|" + spew.Sprint(node.height) + ")"
|
|
*str += spew.Sprint(node.value) + suffix + "\n"
|
|
|
|
if node.children[0] != nil {
|
|
newPrefix := prefix
|
|
if isTail {
|
|
newPrefix += " "
|
|
} else {
|
|
newPrefix += "│ "
|
|
}
|
|
outputfordebug(node.children[0], newPrefix, true, str)
|
|
}
|
|
}
|