structure/avl/avl.go

930 lines
17 KiB
Go

package avl
import (
"474420502.top/eson/structure/compare"
"github.com/davecgh/go-spew/spew"
)
type Node struct {
children [2]*Node
parent *Node
height int
value interface{}
}
func (n *Node) String() string {
if n == nil {
return "nil"
}
p := "nil"
if n.parent != nil {
p = spew.Sprint(n.parent.value)
}
return spew.Sprint(n.value) + "(" + p + "|" + spew.Sprint(n.height) + ")"
}
type Tree struct {
root *Node
size int
compare compare.Compare
}
func New(compare compare.Compare) *Tree {
return &Tree{compare: compare}
}
func (tree *Tree) String() string {
if tree.size == 0 {
return ""
}
str := "AVLTree\n"
output(tree.root, "", true, &str)
return str
}
func (tree *Tree) Iterator() *Iterator {
return initIterator(tree)
}
func (tree *Tree) Size() int {
return tree.size
}
func (tree *Tree) Remove(key interface{}) *Node {
if n, ok := tree.GetNode(key); ok {
tree.size--
if tree.size == 0 {
tree.root = nil
return n
}
left := getHeight(n.children[0])
right := getHeight(n.children[1])
if left == -1 && right == -1 {
p := n.parent
p.children[getRelationship(n)] = nil
tree.fixRemoveHeight(p)
return n
}
var cur *Node
if left > right {
cur = n.children[0]
for cur.children[1] != nil {
cur = cur.children[1]
}
cleft := cur.children[0]
cur.parent.children[getRelationship(cur)] = cleft
if cleft != nil {
cleft.parent = cur.parent
}
} else {
cur = n.children[1]
for cur.children[0] != nil {
cur = cur.children[0]
}
cright := cur.children[1]
cur.parent.children[getRelationship(cur)] = cright
if cright != nil {
cright.parent = cur.parent
}
}
cparent := cur.parent
// 修改为interface 交换
n.value, cur.value = cur.value, n.value
// 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
if cparent == n {
tree.fixRemoveHeight(n)
} else {
tree.fixRemoveHeight(cparent)
}
return cur
}
return nil
}
// Values 返回先序遍历的值
func (tree *Tree) Values() []interface{} {
mszie := 0
if tree.root != nil {
mszie = tree.size
}
result := make([]interface{}, 0, mszie)
tree.Traversal(func(v interface{}) bool {
result = append(result, v)
return true
}, LDR)
return result
}
func (tree *Tree) GetRange(k1, k2 interface{}) (result []interface{}) {
c := tree.compare(k2, k1)
switch c {
case 1:
var min, max *Node
resultmin := tree.getArountNode(k1)
resultmax := tree.getArountNode(k2)
for i := 1; i < 3 && min == nil; i++ {
min = resultmin[i]
}
for i := 1; i > -1 && max == nil; i-- {
max = resultmax[i]
}
if max == nil {
return []interface{}{}
}
result = make([]interface{}, 0, 16)
iter := NewIterator(min)
for iter.Next() {
result = append(result, iter.Value())
if iter.cur == max {
break
}
}
case -1:
var min, max *Node
resultmin := tree.getArountNode(k2)
resultmax := tree.getArountNode(k1)
for i := 1; i < 3 && min == nil; i++ {
min = resultmin[i]
}
for i := 1; i > -1 && max == nil; i-- {
max = resultmax[i]
}
if min == nil {
return []interface{}{}
}
result = make([]interface{}, 0, 16)
iter := NewIterator(max)
for iter.Prev() {
result = append(result, iter.Value())
if iter.cur == min {
break
}
}
case 0:
if n, ok := tree.GetNode(k1); ok {
return []interface{}{n.value}
}
return []interface{}{}
}
return
}
func (tree *Tree) Get(key interface{}) (interface{}, bool) {
n, ok := tree.GetNode(key)
if ok {
return n.value, true
}
return n, false
}
func (tree *Tree) GetAround(key interface{}) (result [3]interface{}) {
an := tree.getArountNode(key)
for i, n := range an {
if n != nil {
result[i] = n.value
}
}
return
}
func (tree *Tree) getArountNode(key interface{}) (result [3]*Node) {
var last *Node
var lastc int
for n := tree.root; n != nil; {
last = n
c := tree.compare(key, n.value)
switch c {
case -1:
n = n.children[0]
lastc = c
case 1:
n = n.children[1]
lastc = c
case 0:
iter := NewIterator(n)
iter.Prev()
for iter.Prev() {
if tree.compare(iter.cur.value, n.value) == 0 {
n = iter.cur
} else {
break
}
}
result[1] = n
n = nil
default:
panic("Get compare only is allowed in -1, 0, 1")
}
}
switch lastc {
case 1:
if result[1] != nil {
result[0] = GetPrev(result[1], 1)
result[2] = GetNext(result[1], 1)
} else {
result[0] = last
result[2] = GetNext(last, 1)
}
case -1:
if result[1] != nil {
result[0] = GetPrev(result[1], 1)
result[2] = GetNext(result[1], 1)
} else {
result[2] = last
result[0] = GetPrev(last, 1)
}
case 0:
if result[1] == nil {
return
}
result[0] = GetPrev(result[1], 1)
result[2] = GetNext(result[1], 1)
// const il = 0
// const ir = 1
// if result[1] == nil {
// return
// }
// l := result[1].children[il]
// r := result[1].children[ir]
// if l == nil {
// result[0] = nil
// } else {
// for l.children[ir] != nil {
// l = l.children[ir]
// }
// result[0] = l
// }
// if r == nil {
// result[2] = nil
// } else {
// for r.children[il] != nil {
// r = r.children[il]
// }
// result[2] = r
// }
}
return
}
func (tree *Tree) GetNode(value interface{}) (*Node, bool) {
for n := tree.root; n != nil; {
switch c := tree.compare(value, n.value); c {
case -1:
n = n.children[0]
case 1:
n = n.children[1]
case 0:
iter := NewIterator(n)
iter.Prev()
for iter.Prev() {
if tree.compare(iter.cur.value, n.value) == 0 {
n = iter.cur
} else {
break
}
}
return n, true
default:
panic("Get compare only is allowed in -1, 0, 1")
}
}
return nil, false
}
func (tree *Tree) Put(value interface{}) {
tree.size++
node := &Node{value: value}
if tree.size == 1 {
tree.root = node
return
}
cur := tree.root
parent := cur.parent
child := -1
for {
if cur == nil {
parent.children[child] = node
node.parent = parent
if node.parent.height == 0 {
tree.fixPutHeight(node.parent)
}
return
}
parent = cur
c := tree.compare(value, cur.value)
child = (c + 2) / 2
cur = cur.children[child]
}
}
type TraversalMethod int
const (
// L = left R = right D = Value(dest)
_ TraversalMethod = iota
//DLR 先值 然后左递归 右递归 下面同理
DLR
//LDR 先从左边有序访问到右边 从小到大
LDR
// LRD 同理
LRD
// DRL 同理
DRL
// RDL 先从右边有序访问到左边 从大到小
RDL
// RLD 同理
RLD
)
// Traversal 遍历的方法 默认是LDR 从小到大 compare 为 l < r
func (tree *Tree) Traversal(every func(v interface{}) bool, traversalMethod ...interface{}) {
if tree.root == nil {
return
}
method := LDR
if len(traversalMethod) != 0 {
method = traversalMethod[0].(TraversalMethod)
}
switch method {
case DLR:
var traverasl func(cur *Node) bool
traverasl = func(cur *Node) bool {
if cur == nil {
return true
}
if !every(cur.value) {
return false
}
if !traverasl(cur.children[0]) {
return false
}
if !traverasl(cur.children[1]) {
return false
}
return true
}
traverasl(tree.root)
case LDR:
var traverasl func(cur *Node) bool
traverasl = func(cur *Node) bool {
if cur == nil {
return true
}
if !traverasl(cur.children[0]) {
return false
}
if !every(cur.value) {
return false
}
if !traverasl(cur.children[1]) {
return false
}
return true
}
traverasl(tree.root)
case LRD:
var traverasl func(cur *Node) bool
traverasl = func(cur *Node) bool {
if cur == nil {
return true
}
if !traverasl(cur.children[0]) {
return false
}
if !traverasl(cur.children[1]) {
return false
}
if !every(cur.value) {
return false
}
return true
}
traverasl(tree.root)
case DRL:
var traverasl func(cur *Node) bool
traverasl = func(cur *Node) bool {
if cur == nil {
return true
}
if !every(cur.value) {
return false
}
if !traverasl(cur.children[0]) {
return false
}
if !traverasl(cur.children[1]) {
return false
}
return true
}
traverasl(tree.root)
case RDL:
var traverasl func(cur *Node) bool
traverasl = func(cur *Node) bool {
if cur == nil {
return true
}
if !traverasl(cur.children[1]) {
return false
}
if !every(cur.value) {
return false
}
if !traverasl(cur.children[0]) {
return false
}
return true
}
traverasl(tree.root)
case RLD:
var traverasl func(cur *Node) bool
traverasl = func(cur *Node) bool {
if cur == nil {
return true
}
if !traverasl(cur.children[1]) {
return false
}
if !traverasl(cur.children[0]) {
return false
}
if !every(cur.value) {
return false
}
return true
}
traverasl(tree.root)
}
}
func (tree *Tree) lrrotate(cur *Node) {
const l = 1
const r = 0
movparent := cur.children[l]
mov := movparent.children[r]
mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
if mov.children[l] != nil {
movparent.children[r] = mov.children[l]
movparent.children[r].parent = movparent
//movparent.children[r].child = l
} else {
movparent.children[r] = nil
}
if mov.children[r] != nil {
mov.children[l] = mov.children[r]
//mov.children[l].child = l
} else {
mov.children[l] = nil
}
if cur.children[r] != nil {
mov.children[r] = cur.children[r]
mov.children[r].parent = mov
} else {
mov.children[r] = nil
}
cur.children[r] = mov
mov.parent = cur
// movparent.size = getChildrenSumSize(movparent) + 1
// mov.size = getChildrenSumSize(mov) + 1
// cur.size = getChildrenSumSize(cur) + 1
mov.height = getMaxChildrenHeight(mov) + 1
movparent.height = getMaxChildrenHeight(movparent) + 1
cur.height = getMaxChildrenHeight(cur) + 1
}
func (tree *Tree) rlrotate(cur *Node) {
const l = 0
const r = 1
movparent := cur.children[l]
mov := movparent.children[r]
mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
if mov.children[l] != nil {
movparent.children[r] = mov.children[l]
movparent.children[r].parent = movparent
} else {
movparent.children[r] = nil
}
if mov.children[r] != nil {
mov.children[l] = mov.children[r]
} else {
mov.children[l] = nil
}
if cur.children[r] != nil {
mov.children[r] = cur.children[r]
mov.children[r].parent = mov
} else {
mov.children[r] = nil
}
cur.children[r] = mov
mov.parent = cur
// movparent.size = getChildrenSumSize(movparent) + 1
// mov.size = getChildrenSumSize(mov) + 1
// cur.size = getChildrenSumSize(cur) + 1
mov.height = getMaxChildrenHeight(mov) + 1
movparent.height = getMaxChildrenHeight(movparent) + 1
cur.height = getMaxChildrenHeight(cur) + 1
}
func (tree *Tree) rrotateex(cur *Node) {
const l = 0
const r = 1
// 1 right 0 left
mov := cur.children[l]
if mov == nil {
return
}
mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
// mov.children[l]不可能为nil
cur.children[l] = mov.children[l]
if mov.children[l] != nil {
mov.children[l].parent = cur
}
// 解决mov节点孩子转移的问题
if mov.children[r] != nil {
mov.children[l] = mov.children[r]
} else {
mov.children[l] = nil
}
if cur.children[r] != nil {
mov.children[r] = cur.children[r]
mov.children[r].parent = mov
} else {
mov.children[r] = nil
}
// 连接转移后的节点 由于mov只是与cur交换值,parent不变
cur.children[r] = mov
mov.height = getMaxChildrenHeight(mov) + 1
cur.height = getMaxChildrenHeight(cur) + 1
}
func (tree *Tree) rrotate(cur *Node) {
const l = 0
const r = 1
// 1 right 0 left
mov := cur.children[l]
mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
// mov.children[l]不可能为nil
mov.children[l].parent = cur
cur.children[l] = mov.children[l]
// 解决mov节点孩子转移的问题
if mov.children[r] != nil {
mov.children[l] = mov.children[r]
} else {
mov.children[l] = nil
}
if cur.children[r] != nil {
mov.children[r] = cur.children[r]
mov.children[r].parent = mov
} else {
mov.children[r] = nil
}
// 连接转移后的节点 由于mov只是与cur交换值,parent不变
cur.children[r] = mov
// mov.size = getChildrenSumSize(mov) + 1
// cur.size = getChildrenSumSize(cur) + 1
mov.height = getMaxChildrenHeight(mov) + 1
cur.height = getMaxChildrenHeight(cur) + 1
}
func (tree *Tree) lrotateex(cur *Node) {
const l = 1
const r = 0
mov := cur.children[l]
if mov == nil {
return
}
mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
// 不可能为nil
cur.children[l] = mov.children[l]
if mov.children[l] != nil {
mov.children[l].parent = cur
}
if mov.children[r] != nil {
mov.children[l] = mov.children[r]
} else {
mov.children[l] = nil
}
if cur.children[r] != nil {
mov.children[r] = cur.children[r]
mov.children[r].parent = mov
} else {
mov.children[r] = nil
}
cur.children[r] = mov
// mov.size = getChildrenSumSize(mov) + 1
// cur.size = getChildrenSumSize(cur) + 1
mov.height = getMaxChildrenHeight(mov) + 1
cur.height = getMaxChildrenHeight(cur) + 1
}
func (tree *Tree) lrotate(cur *Node) {
const l = 1
const r = 0
mov := cur.children[l]
mov.value, cur.value = cur.value, mov.value //交换值达到, 相对位移
// 不可能为nil
mov.children[l].parent = cur
cur.children[l] = mov.children[l]
if mov.children[r] != nil {
mov.children[l] = mov.children[r]
} else {
mov.children[l] = nil
}
if cur.children[r] != nil {
mov.children[r] = cur.children[r]
mov.children[r].parent = mov
} else {
mov.children[r] = nil
}
cur.children[r] = mov
// mov.size = getChildrenSumSize(mov) + 1
// cur.size = getChildrenSumSize(cur) + 1
mov.height = getMaxChildrenHeight(mov) + 1
cur.height = getMaxChildrenHeight(cur) + 1
}
func getMaxAndChildrenHeight(cur *Node) (h1, h2, maxh int) {
h1 = getHeight(cur.children[0])
h2 = getHeight(cur.children[1])
if h1 > h2 {
maxh = h1
} else {
maxh = h2
}
return
}
func getMaxChildrenHeight(cur *Node) int {
h1 := getHeight(cur.children[0])
h2 := getHeight(cur.children[1])
if h1 > h2 {
return h1
}
return h2
}
func getHeight(cur *Node) int {
if cur == nil {
return -1
}
return cur.height
}
func (tree *Tree) fixRemoveHeight(cur *Node) {
for {
lefth, rigthh, lrmax := getMaxAndChildrenHeight(cur)
// 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
curheight := lrmax + 1
cur.height = curheight
// 计算高度的差值 绝对值大于2的时候需要旋转
diff := lefth - rigthh
if diff < -1 {
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
if getHeight(r.children[0]) > getHeight(r.children[1]) {
tree.lrrotate(cur)
} else {
tree.lrotate(cur)
}
} else if diff > 1 {
l := cur.children[0]
if getHeight(l.children[1]) > getHeight(l.children[0]) {
tree.rlrotate(cur)
} else {
tree.rrotate(cur)
}
} else {
if cur.height == curheight {
return
}
}
if cur.parent == nil {
return
}
cur = cur.parent
}
}
func (tree *Tree) fixPutHeight(cur *Node) {
for {
lefth := getHeight(cur.children[0])
rigthh := getHeight(cur.children[1])
// 计算高度的差值 绝对值大于2的时候需要旋转
diff := lefth - rigthh
if diff < -1 {
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
if getHeight(r.children[0]) > getHeight(r.children[1]) {
tree.lrrotate(cur)
} else {
tree.lrotate(cur)
}
} else if diff > 1 {
l := cur.children[0]
if getHeight(l.children[1]) > getHeight(l.children[0]) {
tree.rlrotate(cur)
} else {
tree.rrotate(cur)
}
} else {
// 选择一个child的最大高度 + 1为 高度
if lefth > rigthh {
cur.height = lefth + 1
} else {
cur.height = rigthh + 1
}
}
if cur.parent == nil || cur.height < cur.parent.height {
return
}
cur = cur.parent
}
}
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.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)
}
}
func (tree *Tree) debugString() string {
if tree.size == 0 {
return ""
}
str := "AVLTree\n"
outputfordebug(tree.root, "", true, &str)
return str
}