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 } func New(comparator utils.Comparator) *Tree { return &Tree{comparator: comparator} } func (avl *Tree) String() string { str := "AVLTree\n" if avl.root == nil { return str + "nil" } output(avl.root, "", true, &str) return str } func (avl *Tree) Iterator() *Iterator { return initIterator(avl) } func (avl *Tree) Size() int { if avl.root == nil { return 0 } return avl.root.size } func (avl *Tree) indexNode(idx int) *Node { cur := avl.root if idx >= 0 { for cur != nil { ls := getSize(cur.children[0]) if idx == ls { return cur } else if idx < ls { cur = cur.children[0] } else { idx = idx - ls - 1 cur = cur.children[1] } } } else { idx = -idx - 1 for cur != nil { rs := getSize(cur.children[1]) if idx == rs { return cur } else if idx < rs { cur = cur.children[1] } else { idx = idx - rs - 1 cur = cur.children[0] } } } return nil } func (avl *Tree) Index(idx int) (interface{}, bool) { n := avl.indexNode(idx) if n != nil { return n.value, true } return nil, false } func (avl *Tree) RemoveIndex(idx int) bool { n := avl.indexNode(idx) if n != nil { avl.removeNode(n) return true } return false } func (avl *Tree) removeNode(n *Node) { if avl.root.size == 1 { avl.root = nil // return n return } ls, rs := getChildrenSize(n) if ls == 0 && rs == 0 { p := n.parent p.children[getRelationship(n)] = nil avl.fixRemoveHeight(p) // return n return } var cur *Node if ls > rs { 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 { avl.fixRemoveHeight(n) } else { avl.fixRemoveHeight(cparent) } // return cur return } func (avl *Tree) Remove(key interface{}) bool { if n, ok := avl.GetNode(key); ok { avl.removeNode(n) return true } // return nil return false } // Values 返回先序遍历的值 func (avl *Tree) Values() []interface{} { mszie := 0 if avl.root != nil { mszie = avl.root.size } result := make([]interface{}, 0, mszie) avl.Traversal(func(v interface{}) bool { result = append(result, v) return true }, LDR) return result } func (avl *Tree) GetRange(idx1, idx2 int) (result []interface{}, ok bool) { // 0 -1 if idx1^idx2 < 0 { if idx1 < 0 { idx1 = avl.root.size + idx1 - 1 } else { idx2 = avl.root.size + idx2 - 1 } } if idx1 > idx2 { ok = true if idx1 >= avl.root.size { idx1 = avl.root.size - 1 ok = false } n := avl.indexNode(idx1) iter := NewIterator(n) result = make([]interface{}, 0, idx1-idx2) for i := idx2; i <= idx1; i++ { if iter.Next() { result = append(result, iter.Value()) } else { ok = false return } } return } else { ok = true if idx2 >= avl.root.size { idx2 = avl.root.size - 1 ok = false } if n := avl.indexNode(idx1); n != nil { iter := NewIterator(n) result = make([]interface{}, 0, idx2-idx1) for i := idx1; i <= idx2; i++ { if iter.Prev() { result = append(result, iter.Value()) } else { ok = false return } } return } } return nil, false } 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) 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) { if cur, ok := avl.GetNode(value); ok { var iter *Iterator iter = NewIterator(cur) iter.curPushPrevStack(iter.up) iter.up = iter.getPrevUp(iter.up) if v, ok := iter.tstack.Pop(); ok { result[0] = v.(*Node) // iter.curPushPrevStack(iter.cur) } else { result[0] = iter.up } iter = NewIterator(cur) iter.curPushNextStack(iter.up) iter.up = iter.getNextUp(iter.up) if v, ok := iter.tstack.Pop(); ok { result[2] = v.(*Node) // iter.curPushNextStack(iter.cur) } else { result[2] = iter.up } result[1] = cur } return } 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 := parent.parent fsize := getSize(fixed) if fsize == 3 { lefts, rigths := getChildrenSize(fixed) avl.fix3PutHeight(fixed, lefts, rigths) } return } if cur.size > 9 { ls, rs := cur.children[0].size, cur.children[1].size factor := cur.size / 10 // or factor = 1 if rs >= ls*2+factor || ls >= rs*2+factor { avl.fixPutHeight(cur, ls, rs) } } cur.size++ parent = cur c := avl.comparator(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 func (avl *Tree) Traversal(every func(v interface{}) bool, traversalMethod ...interface{}) { if avl.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(avl.root) case LDR: var traverasl func(cur *Node) bool traverasl = func(cur *Node) bool { if cur == nil { return true } if !traverasl(cur.children[0]) { log.Println(cur) return false } if !every(cur.value) { return false } if !traverasl(cur.children[1]) { return false } return true } traverasl(avl.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(avl.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(avl.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(avl.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(avl.root) } } func (avl *Tree) lrrotate3(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 cur.children[r] = mov mov.parent = cur cur.children[l] = movparent movparent.children[r] = nil cur.children[r] = mov mov.parent = cur // cur.size = 3 // cur.children[r].size = 1 cur.children[l].size = 1 } 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) rlrotate3(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 cur.children[r] = mov mov.parent = cur cur.children[l] = movparent movparent.children[r] = nil cur.children[r] = mov mov.parent = cur // cur.size = 3 // cur.children[r].size = 1 cur.children[l].size = 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) rrotate3(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 cur.children[r] = mov mov.size = 1 cur.children[l] = mov.children[l] cur.children[l].parent = cur mov.children[l] = nil mov.size = 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) lrotate3(cur *Node) { const l = 1 const r = 0 // 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 cur.children[r] = mov mov.size = 1 cur.children[l] = mov.children[l] cur.children[l].parent = cur mov.children[l] = nil mov.size = 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) { for cur != nil { cur.size-- if cur.size > 9 { ls, rs := cur.children[0].size, cur.children[1].size if rs >= ls*2 || ls >= rs*2 { avl.fixPutHeight(cur, ls, rs) } } cur = cur.parent } } func (avl *Tree) fix3PutHeight(cur *Node, lefts, rigths int) { if lefts > rigths { l := cur.children[0] llsize, lrsize := getChildrenSize(l) if lrsize > llsize { avl.rlrotate3(cur) } else { avl.rrotate3(cur) } } else { r := cur.children[1] rlsize, rrsize := getChildrenSize(r) if rlsize > rrsize { avl.lrrotate3(cur) } else { avl.lrotate3(cur) } } } func (avl *Tree) fixPutHeight(cur *Node, lefts, rigths int) { if lefts > rigths { l := cur.children[0] llsize, lrsize := getChildrenSize(l) if lrsize > llsize { avl.rlrotate(cur) } else { avl.rrotate(cur) } } else { 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 }