structure/avlindex/avlindex.go

package avlindex

import (
	"log"

	"github.com/davecgh/go-spew/spew"

	"github.com/emirpasic/gods/utils"
)

type Node struct {
	children [2]*Node
	parent   *Node
	size     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.size) + ")"
}

type Tree struct {
	root       *Node
	comparator utils.Comparator
	count      int
}

func New(comparator utils.Comparator) *Tree {
	return &Tree{comparator: comparator}
}

func (avl *Tree) String() string {
	str := "AVLTree\n"
	output(avl.root, "", true, &str)

	return str
}

func (avl *Tree) Iterator() *Iterator {
	return initIterator(avl)
}

func (avl *Tree) Size() int {
	return avl.root.size
}

func (avl *Tree) Remove(key interface{}) *Node {
	return nil
}

func (avl *Tree) Get(key interface{}) (interface{}, bool) {
	n, ok := avl.GetNode(key)
	if ok {
		return n.value, true
	}
	return n, false
}

func (avl *Tree) GetRange(min, max interface{}) []interface{} {
	return nil
}

func (avl *Tree) GetAround(key interface{}) (result [3]interface{}) {
	an := avl.GetAroundNode(key)
	for i, n := range an {
		if n != nil {
			result[i] = n.value
		}
	}
	return
}

func (avl *Tree) GetAroundNode(value interface{}) (result [3]*Node) {
	n := avl.root

	for {

		if n == nil {
			return
		}

		lastc := 0
		switch c := avl.comparator(value, n.value); c {
		case -1:
			if c != -lastc {
				result[0] = n
			}
			lastc = c
			n = n.children[0]
		case 1:
			if c != -lastc {
				result[2] = n
			}
			lastc = c
			n = n.children[1]
		case 0:

			switch lastc {
			case -1:
				if n.children[1] != nil {
					result[0] = n.children[1]
				}
			case 1:
				if n.children[0] != nil {
					result[2] = n.children[0]
				}
			case 0:

				if n.children[1] != nil {
					result[0] = n.children[1]
				}
				if n.children[0] != nil {
					result[2] = n.children[0]
				}

				result[1] = n
				return
			}

		default:
			panic("Get comparator only is allowed in -1, 0, 1")
		}

	}
}
func (avl *Tree) GetNode(value interface{}) (*Node, bool) {

	for n := avl.root; n != nil; {
		switch c := avl.comparator(value, n.value); c {
		case -1:
			n = n.children[0]
		case 1:
			n = n.children[1]
		case 0:
			return n, true
		default:
			panic("Get comparator only is allowed in -1, 0, 1")
		}
	}
	return nil, false
}

func (avl *Tree) Put(value interface{}) {

	node := &Node{value: value, size: 1}
	if avl.root == nil {
		avl.root = node
		return
	}

	cur := avl.root
	parent := cur.parent
	child := -1

	for {

		if cur == nil {
			parent.children[child] = node
			node.parent = parent

			fixed := node.parent.parent

			for {
				switch fsize := getSize(fixed); fsize {
				case 3, 5:
					log.Println(fsize)
					lefts, rigths := getChildrenSize(fixed)
					avl.fixPutHeight(fixed, lefts, rigths)
					fixed = fixed.parent
				default:
					return
				}
			}
		}

		if cur.size > 7 {
			ls, rs := cur.children[0].size, cur.children[1].size
			if rs >= ls*2 || ls >= rs*2 {
				// ll, lr := getChildrenSize(cur.children[0])
				// rl, rr := getChildrenSize(cur.children[1])
				avl.fixPutHeight(cur, ls, rs)
			}
		}

		cur.size++
		parent = cur
		c := avl.comparator(value, cur.value)
		child = (c + 2) / 2
		cur = cur.children[child]
	}

}

func (avl *Tree) debugString() string {
	str := "AVLTree\n"
	outputfordebug(avl.root, "", true, &str)
	return str
}

func (avl *Tree) TraversalBreadth() (result []interface{}) {
	result = make([]interface{}, 0, avl.root.size)
	var traverasl func(cur *Node)
	traverasl = func(cur *Node) {
		if cur == nil {
			return
		}
		result = append(result, cur.value)
		traverasl(cur.children[0])
		traverasl(cur.children[1])
	}
	traverasl(avl.root)
	return
}

func (avl *Tree) TraversalDepth(leftright int) (result []interface{}) {
	result = make([]interface{}, 0, avl.root.size)
	if leftright < 0 {
		var traverasl func(cur *Node)
		traverasl = func(cur *Node) {
			if cur == nil {
				return
			}
			traverasl(cur.children[0])
			result = append(result, cur.value)
			traverasl(cur.children[1])
		}
		traverasl(avl.root)
	} else {
		var traverasl func(cur *Node)
		traverasl = func(cur *Node) {
			if cur == nil {
				return
			}
			traverasl(cur.children[1])
			result = append(result, cur.value)
			traverasl(cur.children[0])
		}
		traverasl(avl.root)
	}

	return
}

func (avl *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

	// cur.size = 3
	// cur.children[0].size = 1
	// cur.children[1].size = 1

	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 (avl *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
}

func (avl *Tree) rrotate(cur *Node) {

	const l = 0
	const r = 1
	// 1 right 0 left
	mov := cur.children[l]

	// lsize, rsize := getChildrenHeight(cur)
	// movrsize := getSize(mov.children[r])

	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

	// cur.size = 3
	// cur.children[0].size = 1
	// cur.children[1].size = 1

	mov.size = getChildrenSumSize(mov) + 1
	cur.size = getChildrenSumSize(cur) + 1
	// cur.height = getMaxChildrenHeight(cur) + 1
}

func (avl *Tree) lrotate(cur *Node) {

	const l = 1
	const r = 0
	// 1 right 0 left
	mov := cur.children[l]

	// lsize, rsize := getChildrenHeight(cur)
	// movrsize := getSize(mov.children[r])

	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

	// cur.size = 3
	// cur.children[0].size = 1
	// cur.children[1].size = 1

	mov.size = getChildrenSumSize(mov) + 1
	cur.size = getChildrenSumSize(cur) + 1
}

func getChildrenSumSize(cur *Node) int {
	return getSize(cur.children[0]) + getSize(cur.children[1])
}

func getChildrenSize(cur *Node) (int, int) {
	return getSize(cur.children[0]), getSize(cur.children[1])
}

func getSize(cur *Node) int {
	if cur == nil {
		return 0
	}
	return cur.size
}

func (avl *Tree) fixRemoveHeight(cur *Node) {

}

func abs(n int) int {
	y := n >> 31
	return (n ^ y) - y
}

func (avl *Tree) fixPutHeight(cur *Node, lefts, rigths int) {
	avl.count++
	if lefts < rigths {
		r := cur.children[1]
		rlsize, rrsize := getChildrenSize(r)
		if rlsize > rrsize {
			avl.lrrotate(cur)
		} else {
			avl.lrotate(cur)
		}
	} else {
		l := cur.children[0]
		llsize, lrsize := getChildrenSize(l)
		if lrsize > llsize {
			avl.rlrotate(cur)
		} else {
			avl.rrotate(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)
	}
}