672 lines
13 KiB
Go
672 lines
13 KiB
Go
package avlindex
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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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size int
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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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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.size) + ")"
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}
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type Tree struct {
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root *Node
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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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str := "AVLTree\n"
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if avl.root == nil {
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return str + "nil"
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}
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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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if avl.root == nil {
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return 0
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}
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return avl.root.size
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}
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func (avl *Tree) Index(idx int) (interface{}, bool) {
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cur := avl.root
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if idx >= 0 {
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for cur != nil {
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ls := getSize(cur.children[0])
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if idx == ls {
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return cur.value, true
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} else if idx < ls {
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cur = cur.children[0]
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} else {
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idx = idx - ls - 1
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cur = cur.children[1]
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}
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}
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} else {
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idx = -idx - 1
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for cur != nil {
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rs := getSize(cur.children[1])
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if idx == rs {
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return cur.value, true
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} else if idx < rs {
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cur = cur.children[1]
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} else {
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idx = idx - rs - 1
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cur = cur.children[0]
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}
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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) Remove(key interface{}) *Node {
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if n, ok := avl.GetNode(key); ok {
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if avl.root.size == 1 {
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avl.root = nil
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return n
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}
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ls, rs := getChildrenSize(n)
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if ls == 0 && rs == 0 {
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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 ls > rs {
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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.value, cur.value = cur.value, 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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// Values 返回先序遍历的值
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func (avl *Tree) Values() []interface{} {
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mszie := 0
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if avl.root != nil {
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mszie = avl.root.size
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}
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result := make([]interface{}, 0, mszie)
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avl.Traversal(func(v interface{}) {
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result = append(result, v)
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}, LDR)
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return result
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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(value interface{}) (result [3]*Node) {
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if cur, ok := avl.GetNode(value); ok {
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var iter *Iterator
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iter = NewIterator(cur)
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iter.curPushPrevStack(iter.up)
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iter.up = iter.getPrevUp(iter.up)
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if v, ok := iter.tstack.Pop(); ok {
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result[0] = v.(*Node)
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// iter.curPushPrevStack(iter.cur)
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} else {
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result[0] = iter.up
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}
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iter = NewIterator(cur)
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iter.curPushNextStack(iter.up)
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iter.up = iter.getNextUp(iter.up)
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if v, ok := iter.tstack.Pop(); ok {
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result[2] = v.(*Node)
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// iter.curPushNextStack(iter.cur)
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} else {
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result[2] = iter.up
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}
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result[1] = cur
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}
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return
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}
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func (avl *Tree) GetNode(value interface{}) (*Node, bool) {
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for n := avl.root; n != nil; {
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switch c := avl.comparator(value, n.value); 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(value interface{}) {
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node := &Node{value: value, size: 1}
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if avl.root == nil {
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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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fixed := parent.parent
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fsize := getSize(fixed)
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if fsize == 3 {
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lefts, rigths := getChildrenSize(fixed)
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avl.fixPutHeight(fixed, lefts, rigths)
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}
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return
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}
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if cur.size > 9 {
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ls, rs := cur.children[0].size, cur.children[1].size
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if rs >= ls*2 || ls >= rs*2 {
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avl.fixPutHeight(cur, ls, rs)
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}
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}
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cur.size++
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parent = cur
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c := avl.comparator(value, cur.value)
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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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type TraversalMethod int
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const (
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// L = left R = right D = Value(dest)
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_ TraversalMethod = iota
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//DLR 先值 然后左递归 右递归 下面同理
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DLR
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//LDR 先从左边有序访问到右边 从小到大
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LDR
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// LRD 同理
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LRD
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// DRL 同理
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DRL
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// RDL 先从右边有序访问到左边 从大到小
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RDL
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// RLD 同理
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RLD
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)
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// Traversal 遍历的方法
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func (avl *Tree) Traversal(every func(v interface{}), traversalMethod ...interface{}) {
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if avl.root == nil {
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return
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}
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method := DLR
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if len(traversalMethod) != 0 {
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method = traversalMethod[0].(TraversalMethod)
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}
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switch method {
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case DLR:
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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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every(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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case LDR:
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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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every(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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case LRD:
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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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traverasl(cur.children[1])
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every(cur.value)
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}
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traverasl(avl.root)
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case DRL:
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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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every(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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case RDL:
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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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every(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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case RLD:
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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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traverasl(cur.children[0])
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every(cur.value)
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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.value, cur.value = cur.value, 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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// cur.size = 3
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// cur.children[0].size = 1
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// cur.children[1].size = 1
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movparent.size = getChildrenSumSize(movparent) + 1
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mov.size = getChildrenSumSize(mov) + 1
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cur.size = getChildrenSumSize(cur) + 1
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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.value, cur.value = cur.value, 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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movparent.size = getChildrenSumSize(movparent) + 1
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mov.size = getChildrenSumSize(mov) + 1
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cur.size = getChildrenSumSize(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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// lsize, rsize := getChildrenHeight(cur)
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// movrsize := getSize(mov.children[r])
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mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
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// mov.children[l]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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// cur.size = 3
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// cur.children[0].size = 1
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// cur.children[1].size = 1
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mov.size = getChildrenSumSize(mov) + 1
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cur.size = getChildrenSumSize(cur) + 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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// 1 right 0 left
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mov := cur.children[l]
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// lsize, rsize := getChildrenHeight(cur)
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// movrsize := getSize(mov.children[r])
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mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
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// mov.children[l]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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// cur.size = 3
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// cur.children[0].size = 1
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// cur.children[1].size = 1
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mov.size = getChildrenSumSize(mov) + 1
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cur.size = getChildrenSumSize(cur) + 1
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}
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func getChildrenSumSize(cur *Node) int {
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return getSize(cur.children[0]) + getSize(cur.children[1])
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}
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func getChildrenSize(cur *Node) (int, int) {
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return getSize(cur.children[0]), getSize(cur.children[1])
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}
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func getSize(cur *Node) int {
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if cur == nil {
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return 0
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}
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return cur.size
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}
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func (avl *Tree) fixRemoveHeight(cur *Node) {
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for cur != nil {
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cur.size--
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if cur.size > 9 {
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ls, rs := cur.children[0].size, cur.children[1].size
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if rs >= ls*2 || ls >= rs*2 {
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avl.fixPutHeight(cur, ls, rs)
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}
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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, lefts, rigths int) {
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if lefts > rigths {
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l := cur.children[0]
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llsize, lrsize := getChildrenSize(l)
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if lrsize > llsize {
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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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r := cur.children[1]
|
|
rlsize, rrsize := getChildrenSize(r)
|
|
if rlsize > rrsize {
|
|
avl.lrrotate(cur)
|
|
} else {
|
|
avl.lrotate(cur)
|
|
}
|
|
}
|
|
}
|
|
|
|
func output(node *Node, prefix string, isTail bool, str *string) {
|
|
|
|
if node.children[1] != nil {
|
|
newPrefix := prefix
|
|
if isTail {
|
|
newPrefix += "│ "
|
|
} else {
|
|
newPrefix += " "
|
|
}
|
|
output(node.children[1], newPrefix, false, str)
|
|
}
|
|
*str += prefix
|
|
if isTail {
|
|
*str += "└── "
|
|
} else {
|
|
*str += "┌── "
|
|
}
|
|
|
|
*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.size) + ")"
|
|
*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)
|
|
}
|
|
}
|
|
|
|
func (avl *Tree) debugString() string {
|
|
str := "AVLTree\n"
|
|
if avl.root == nil {
|
|
return str + "nil"
|
|
}
|
|
outputfordebug(avl.root, "", true, &str)
|
|
return str
|
|
}
|