996 lines
No EOL
22 KiB
JavaScript
996 lines
No EOL
22 KiB
JavaScript
"use strict"
|
|
|
|
module.exports = createRBTree
|
|
|
|
var RED = 0
|
|
var BLACK = 1
|
|
|
|
function RBNode(color, key, value, left, right, count) {
|
|
this._color = color
|
|
this.key = key
|
|
this.value = value
|
|
this.left = left
|
|
this.right = right
|
|
this._count = count
|
|
}
|
|
|
|
function cloneNode(node) {
|
|
return new RBNode(node._color, node.key, node.value, node.left, node.right, node._count)
|
|
}
|
|
|
|
function repaint(color, node) {
|
|
return new RBNode(color, node.key, node.value, node.left, node.right, node._count)
|
|
}
|
|
|
|
function recount(node) {
|
|
node._count = 1 + (node.left ? node.left._count : 0) + (node.right ? node.right._count : 0)
|
|
}
|
|
|
|
function RedBlackTree(compare, root) {
|
|
this._compare = compare
|
|
this.root = root
|
|
}
|
|
|
|
var proto = RedBlackTree.prototype
|
|
|
|
Object.defineProperty(proto, "keys", {
|
|
get: function() {
|
|
var result = []
|
|
this.forEach(function(k,v) {
|
|
result.push(k)
|
|
})
|
|
return result
|
|
}
|
|
})
|
|
|
|
Object.defineProperty(proto, "values", {
|
|
get: function() {
|
|
var result = []
|
|
this.forEach(function(k,v) {
|
|
result.push(v)
|
|
})
|
|
return result
|
|
}
|
|
})
|
|
|
|
//Returns the number of nodes in the tree
|
|
Object.defineProperty(proto, "length", {
|
|
get: function() {
|
|
if(this.root) {
|
|
return this.root._count
|
|
}
|
|
return 0
|
|
}
|
|
})
|
|
|
|
//Insert a new item into the tree
|
|
proto.insert = function(key, value) {
|
|
var cmp = this._compare
|
|
//Find point to insert new node at
|
|
var n = this.root
|
|
var n_stack = []
|
|
var d_stack = []
|
|
while(n) {
|
|
var d = cmp(key, n.key)
|
|
n_stack.push(n)
|
|
d_stack.push(d)
|
|
if(d <= 0) {
|
|
n = n.left
|
|
} else {
|
|
n = n.right
|
|
}
|
|
}
|
|
//Rebuild path to leaf node
|
|
n_stack.push(new RBNode(RED, key, value, null, null, 1))
|
|
for(var s=n_stack.length-2; s>=0; --s) {
|
|
var n = n_stack[s]
|
|
if(d_stack[s] <= 0) {
|
|
n_stack[s] = new RBNode(n._color, n.key, n.value, n_stack[s+1], n.right, n._count+1)
|
|
} else {
|
|
n_stack[s] = new RBNode(n._color, n.key, n.value, n.left, n_stack[s+1], n._count+1)
|
|
}
|
|
}
|
|
//Rebalance tree using rotations
|
|
//console.log("start insert", key, d_stack)
|
|
for(var s=n_stack.length-1; s>1; --s) {
|
|
var p = n_stack[s-1]
|
|
var n = n_stack[s]
|
|
if(p._color === BLACK || n._color === BLACK) {
|
|
break
|
|
}
|
|
var pp = n_stack[s-2]
|
|
if(pp.left === p) {
|
|
if(p.left === n) {
|
|
var y = pp.right
|
|
if(y && y._color === RED) {
|
|
//console.log("LLr")
|
|
p._color = BLACK
|
|
pp.right = repaint(BLACK, y)
|
|
pp._color = RED
|
|
s -= 1
|
|
} else {
|
|
//console.log("LLb")
|
|
pp._color = RED
|
|
pp.left = p.right
|
|
p._color = BLACK
|
|
p.right = pp
|
|
n_stack[s-2] = p
|
|
n_stack[s-1] = n
|
|
recount(pp)
|
|
recount(p)
|
|
if(s >= 3) {
|
|
var ppp = n_stack[s-3]
|
|
if(ppp.left === pp) {
|
|
ppp.left = p
|
|
} else {
|
|
ppp.right = p
|
|
}
|
|
}
|
|
break
|
|
}
|
|
} else {
|
|
var y = pp.right
|
|
if(y && y._color === RED) {
|
|
//console.log("LRr")
|
|
p._color = BLACK
|
|
pp.right = repaint(BLACK, y)
|
|
pp._color = RED
|
|
s -= 1
|
|
} else {
|
|
//console.log("LRb")
|
|
p.right = n.left
|
|
pp._color = RED
|
|
pp.left = n.right
|
|
n._color = BLACK
|
|
n.left = p
|
|
n.right = pp
|
|
n_stack[s-2] = n
|
|
n_stack[s-1] = p
|
|
recount(pp)
|
|
recount(p)
|
|
recount(n)
|
|
if(s >= 3) {
|
|
var ppp = n_stack[s-3]
|
|
if(ppp.left === pp) {
|
|
ppp.left = n
|
|
} else {
|
|
ppp.right = n
|
|
}
|
|
}
|
|
break
|
|
}
|
|
}
|
|
} else {
|
|
if(p.right === n) {
|
|
var y = pp.left
|
|
if(y && y._color === RED) {
|
|
//console.log("RRr", y.key)
|
|
p._color = BLACK
|
|
pp.left = repaint(BLACK, y)
|
|
pp._color = RED
|
|
s -= 1
|
|
} else {
|
|
//console.log("RRb")
|
|
pp._color = RED
|
|
pp.right = p.left
|
|
p._color = BLACK
|
|
p.left = pp
|
|
n_stack[s-2] = p
|
|
n_stack[s-1] = n
|
|
recount(pp)
|
|
recount(p)
|
|
if(s >= 3) {
|
|
var ppp = n_stack[s-3]
|
|
if(ppp.right === pp) {
|
|
ppp.right = p
|
|
} else {
|
|
ppp.left = p
|
|
}
|
|
}
|
|
break
|
|
}
|
|
} else {
|
|
var y = pp.left
|
|
if(y && y._color === RED) {
|
|
//console.log("RLr")
|
|
p._color = BLACK
|
|
pp.left = repaint(BLACK, y)
|
|
pp._color = RED
|
|
s -= 1
|
|
} else {
|
|
//console.log("RLb")
|
|
p.left = n.right
|
|
pp._color = RED
|
|
pp.right = n.left
|
|
n._color = BLACK
|
|
n.right = p
|
|
n.left = pp
|
|
n_stack[s-2] = n
|
|
n_stack[s-1] = p
|
|
recount(pp)
|
|
recount(p)
|
|
recount(n)
|
|
if(s >= 3) {
|
|
var ppp = n_stack[s-3]
|
|
if(ppp.right === pp) {
|
|
ppp.right = n
|
|
} else {
|
|
ppp.left = n
|
|
}
|
|
}
|
|
break
|
|
}
|
|
}
|
|
}
|
|
}
|
|
//Return new tree
|
|
n_stack[0]._color = BLACK
|
|
return new RedBlackTree(cmp, n_stack[0])
|
|
}
|
|
|
|
|
|
//Visit all nodes inorder
|
|
function doVisitFull(visit, node) {
|
|
if(node.left) {
|
|
var v = doVisitFull(visit, node.left)
|
|
if(v) { return v }
|
|
}
|
|
var v = visit(node.key, node.value)
|
|
if(v) { return v }
|
|
if(node.right) {
|
|
return doVisitFull(visit, node.right)
|
|
}
|
|
}
|
|
|
|
//Visit half nodes in order
|
|
function doVisitHalf(lo, compare, visit, node) {
|
|
var l = compare(lo, node.key)
|
|
if(l <= 0) {
|
|
if(node.left) {
|
|
var v = doVisitHalf(lo, compare, visit, node.left)
|
|
if(v) { return v }
|
|
}
|
|
var v = visit(node.key, node.value)
|
|
if(v) { return v }
|
|
}
|
|
if(node.right) {
|
|
return doVisitHalf(lo, compare, visit, node.right)
|
|
}
|
|
}
|
|
|
|
//Visit all nodes within a range
|
|
function doVisit(lo, hi, compare, visit, node) {
|
|
var l = compare(lo, node.key)
|
|
var h = compare(hi, node.key)
|
|
var v
|
|
if(l <= 0) {
|
|
if(node.left) {
|
|
v = doVisit(lo, hi, compare, visit, node.left)
|
|
if(v) { return v }
|
|
}
|
|
if(h > 0) {
|
|
v = visit(node.key, node.value)
|
|
if(v) { return v }
|
|
}
|
|
}
|
|
if(h > 0 && node.right) {
|
|
return doVisit(lo, hi, compare, visit, node.right)
|
|
}
|
|
}
|
|
|
|
|
|
proto.forEach = function rbTreeForEach(visit, lo, hi) {
|
|
if(!this.root) {
|
|
return
|
|
}
|
|
switch(arguments.length) {
|
|
case 1:
|
|
return doVisitFull(visit, this.root)
|
|
break
|
|
|
|
case 2:
|
|
return doVisitHalf(lo, this._compare, visit, this.root)
|
|
break
|
|
|
|
case 3:
|
|
if(this._compare(lo, hi) >= 0) {
|
|
return
|
|
}
|
|
return doVisit(lo, hi, this._compare, visit, this.root)
|
|
break
|
|
}
|
|
}
|
|
|
|
//First item in list
|
|
Object.defineProperty(proto, "begin", {
|
|
get: function() {
|
|
var stack = []
|
|
var n = this.root
|
|
while(n) {
|
|
stack.push(n)
|
|
n = n.left
|
|
}
|
|
return new RedBlackTreeIterator(this, stack)
|
|
}
|
|
})
|
|
|
|
//Last item in list
|
|
Object.defineProperty(proto, "end", {
|
|
get: function() {
|
|
var stack = []
|
|
var n = this.root
|
|
while(n) {
|
|
stack.push(n)
|
|
n = n.right
|
|
}
|
|
return new RedBlackTreeIterator(this, stack)
|
|
}
|
|
})
|
|
|
|
//Find the ith item in the tree
|
|
proto.at = function(idx) {
|
|
if(idx < 0) {
|
|
return new RedBlackTreeIterator(this, [])
|
|
}
|
|
var n = this.root
|
|
var stack = []
|
|
while(true) {
|
|
stack.push(n)
|
|
if(n.left) {
|
|
if(idx < n.left._count) {
|
|
n = n.left
|
|
continue
|
|
}
|
|
idx -= n.left._count
|
|
}
|
|
if(!idx) {
|
|
return new RedBlackTreeIterator(this, stack)
|
|
}
|
|
idx -= 1
|
|
if(n.right) {
|
|
if(idx >= n.right._count) {
|
|
break
|
|
}
|
|
n = n.right
|
|
} else {
|
|
break
|
|
}
|
|
}
|
|
return new RedBlackTreeIterator(this, [])
|
|
}
|
|
|
|
proto.ge = function(key) {
|
|
var cmp = this._compare
|
|
var n = this.root
|
|
var stack = []
|
|
var last_ptr = 0
|
|
while(n) {
|
|
var d = cmp(key, n.key)
|
|
stack.push(n)
|
|
if(d <= 0) {
|
|
last_ptr = stack.length
|
|
}
|
|
if(d <= 0) {
|
|
n = n.left
|
|
} else {
|
|
n = n.right
|
|
}
|
|
}
|
|
stack.length = last_ptr
|
|
return new RedBlackTreeIterator(this, stack)
|
|
}
|
|
|
|
proto.gt = function(key) {
|
|
var cmp = this._compare
|
|
var n = this.root
|
|
var stack = []
|
|
var last_ptr = 0
|
|
while(n) {
|
|
var d = cmp(key, n.key)
|
|
stack.push(n)
|
|
if(d < 0) {
|
|
last_ptr = stack.length
|
|
}
|
|
if(d < 0) {
|
|
n = n.left
|
|
} else {
|
|
n = n.right
|
|
}
|
|
}
|
|
stack.length = last_ptr
|
|
return new RedBlackTreeIterator(this, stack)
|
|
}
|
|
|
|
proto.lt = function(key) {
|
|
var cmp = this._compare
|
|
var n = this.root
|
|
var stack = []
|
|
var last_ptr = 0
|
|
while(n) {
|
|
var d = cmp(key, n.key)
|
|
stack.push(n)
|
|
if(d > 0) {
|
|
last_ptr = stack.length
|
|
}
|
|
if(d <= 0) {
|
|
n = n.left
|
|
} else {
|
|
n = n.right
|
|
}
|
|
}
|
|
stack.length = last_ptr
|
|
return new RedBlackTreeIterator(this, stack)
|
|
}
|
|
|
|
proto.le = function(key) {
|
|
var cmp = this._compare
|
|
var n = this.root
|
|
var stack = []
|
|
var last_ptr = 0
|
|
while(n) {
|
|
var d = cmp(key, n.key)
|
|
stack.push(n)
|
|
if(d >= 0) {
|
|
last_ptr = stack.length
|
|
}
|
|
if(d < 0) {
|
|
n = n.left
|
|
} else {
|
|
n = n.right
|
|
}
|
|
}
|
|
stack.length = last_ptr
|
|
return new RedBlackTreeIterator(this, stack)
|
|
}
|
|
|
|
//Finds the item with key if it exists
|
|
proto.find = function(key) {
|
|
var cmp = this._compare
|
|
var n = this.root
|
|
var stack = []
|
|
while(n) {
|
|
var d = cmp(key, n.key)
|
|
stack.push(n)
|
|
if(d === 0) {
|
|
return new RedBlackTreeIterator(this, stack)
|
|
}
|
|
if(d <= 0) {
|
|
n = n.left
|
|
} else {
|
|
n = n.right
|
|
}
|
|
}
|
|
return new RedBlackTreeIterator(this, [])
|
|
}
|
|
|
|
//Removes item with key from tree
|
|
proto.remove = function(key) {
|
|
var iter = this.find(key)
|
|
if(iter) {
|
|
return iter.remove()
|
|
}
|
|
return this
|
|
}
|
|
|
|
//Returns the item at `key`
|
|
proto.get = function(key) {
|
|
var cmp = this._compare
|
|
var n = this.root
|
|
while(n) {
|
|
var d = cmp(key, n.key)
|
|
if(d === 0) {
|
|
return n.value
|
|
}
|
|
if(d <= 0) {
|
|
n = n.left
|
|
} else {
|
|
n = n.right
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
//Iterator for red black tree
|
|
function RedBlackTreeIterator(tree, stack) {
|
|
this.tree = tree
|
|
this._stack = stack
|
|
}
|
|
|
|
var iproto = RedBlackTreeIterator.prototype
|
|
|
|
//Test if iterator is valid
|
|
Object.defineProperty(iproto, "valid", {
|
|
get: function() {
|
|
return this._stack.length > 0
|
|
}
|
|
})
|
|
|
|
//Node of the iterator
|
|
Object.defineProperty(iproto, "node", {
|
|
get: function() {
|
|
if(this._stack.length > 0) {
|
|
return this._stack[this._stack.length-1]
|
|
}
|
|
return null
|
|
},
|
|
enumerable: true
|
|
})
|
|
|
|
//Makes a copy of an iterator
|
|
iproto.clone = function() {
|
|
return new RedBlackTreeIterator(this.tree, this._stack.slice())
|
|
}
|
|
|
|
//Swaps two nodes
|
|
function swapNode(n, v) {
|
|
n.key = v.key
|
|
n.value = v.value
|
|
n.left = v.left
|
|
n.right = v.right
|
|
n._color = v._color
|
|
n._count = v._count
|
|
}
|
|
|
|
//Fix up a double black node in a tree
|
|
function fixDoubleBlack(stack) {
|
|
var n, p, s, z
|
|
for(var i=stack.length-1; i>=0; --i) {
|
|
n = stack[i]
|
|
if(i === 0) {
|
|
n._color = BLACK
|
|
return
|
|
}
|
|
//console.log("visit node:", n.key, i, stack[i].key, stack[i-1].key)
|
|
p = stack[i-1]
|
|
if(p.left === n) {
|
|
//console.log("left child")
|
|
s = p.right
|
|
if(s.right && s.right._color === RED) {
|
|
//console.log("case 1: right sibling child red")
|
|
s = p.right = cloneNode(s)
|
|
z = s.right = cloneNode(s.right)
|
|
p.right = s.left
|
|
s.left = p
|
|
s.right = z
|
|
s._color = p._color
|
|
n._color = BLACK
|
|
p._color = BLACK
|
|
z._color = BLACK
|
|
recount(p)
|
|
recount(s)
|
|
if(i > 1) {
|
|
var pp = stack[i-2]
|
|
if(pp.left === p) {
|
|
pp.left = s
|
|
} else {
|
|
pp.right = s
|
|
}
|
|
}
|
|
stack[i-1] = s
|
|
return
|
|
} else if(s.left && s.left._color === RED) {
|
|
//console.log("case 1: left sibling child red")
|
|
s = p.right = cloneNode(s)
|
|
z = s.left = cloneNode(s.left)
|
|
p.right = z.left
|
|
s.left = z.right
|
|
z.left = p
|
|
z.right = s
|
|
z._color = p._color
|
|
p._color = BLACK
|
|
s._color = BLACK
|
|
n._color = BLACK
|
|
recount(p)
|
|
recount(s)
|
|
recount(z)
|
|
if(i > 1) {
|
|
var pp = stack[i-2]
|
|
if(pp.left === p) {
|
|
pp.left = z
|
|
} else {
|
|
pp.right = z
|
|
}
|
|
}
|
|
stack[i-1] = z
|
|
return
|
|
}
|
|
if(s._color === BLACK) {
|
|
if(p._color === RED) {
|
|
//console.log("case 2: black sibling, red parent", p.right.value)
|
|
p._color = BLACK
|
|
p.right = repaint(RED, s)
|
|
return
|
|
} else {
|
|
//console.log("case 2: black sibling, black parent", p.right.value)
|
|
p.right = repaint(RED, s)
|
|
continue
|
|
}
|
|
} else {
|
|
//console.log("case 3: red sibling")
|
|
s = cloneNode(s)
|
|
p.right = s.left
|
|
s.left = p
|
|
s._color = p._color
|
|
p._color = RED
|
|
recount(p)
|
|
recount(s)
|
|
if(i > 1) {
|
|
var pp = stack[i-2]
|
|
if(pp.left === p) {
|
|
pp.left = s
|
|
} else {
|
|
pp.right = s
|
|
}
|
|
}
|
|
stack[i-1] = s
|
|
stack[i] = p
|
|
if(i+1 < stack.length) {
|
|
stack[i+1] = n
|
|
} else {
|
|
stack.push(n)
|
|
}
|
|
i = i+2
|
|
}
|
|
} else {
|
|
//console.log("right child")
|
|
s = p.left
|
|
if(s.left && s.left._color === RED) {
|
|
//console.log("case 1: left sibling child red", p.value, p._color)
|
|
s = p.left = cloneNode(s)
|
|
z = s.left = cloneNode(s.left)
|
|
p.left = s.right
|
|
s.right = p
|
|
s.left = z
|
|
s._color = p._color
|
|
n._color = BLACK
|
|
p._color = BLACK
|
|
z._color = BLACK
|
|
recount(p)
|
|
recount(s)
|
|
if(i > 1) {
|
|
var pp = stack[i-2]
|
|
if(pp.right === p) {
|
|
pp.right = s
|
|
} else {
|
|
pp.left = s
|
|
}
|
|
}
|
|
stack[i-1] = s
|
|
return
|
|
} else if(s.right && s.right._color === RED) {
|
|
//console.log("case 1: right sibling child red")
|
|
s = p.left = cloneNode(s)
|
|
z = s.right = cloneNode(s.right)
|
|
p.left = z.right
|
|
s.right = z.left
|
|
z.right = p
|
|
z.left = s
|
|
z._color = p._color
|
|
p._color = BLACK
|
|
s._color = BLACK
|
|
n._color = BLACK
|
|
recount(p)
|
|
recount(s)
|
|
recount(z)
|
|
if(i > 1) {
|
|
var pp = stack[i-2]
|
|
if(pp.right === p) {
|
|
pp.right = z
|
|
} else {
|
|
pp.left = z
|
|
}
|
|
}
|
|
stack[i-1] = z
|
|
return
|
|
}
|
|
if(s._color === BLACK) {
|
|
if(p._color === RED) {
|
|
//console.log("case 2: black sibling, red parent")
|
|
p._color = BLACK
|
|
p.left = repaint(RED, s)
|
|
return
|
|
} else {
|
|
//console.log("case 2: black sibling, black parent")
|
|
p.left = repaint(RED, s)
|
|
continue
|
|
}
|
|
} else {
|
|
//console.log("case 3: red sibling")
|
|
s = cloneNode(s)
|
|
p.left = s.right
|
|
s.right = p
|
|
s._color = p._color
|
|
p._color = RED
|
|
recount(p)
|
|
recount(s)
|
|
if(i > 1) {
|
|
var pp = stack[i-2]
|
|
if(pp.right === p) {
|
|
pp.right = s
|
|
} else {
|
|
pp.left = s
|
|
}
|
|
}
|
|
stack[i-1] = s
|
|
stack[i] = p
|
|
if(i+1 < stack.length) {
|
|
stack[i+1] = n
|
|
} else {
|
|
stack.push(n)
|
|
}
|
|
i = i+2
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//Removes item at iterator from tree
|
|
iproto.remove = function() {
|
|
var stack = this._stack
|
|
if(stack.length === 0) {
|
|
return this.tree
|
|
}
|
|
//First copy path to node
|
|
var cstack = new Array(stack.length)
|
|
var n = stack[stack.length-1]
|
|
cstack[cstack.length-1] = new RBNode(n._color, n.key, n.value, n.left, n.right, n._count)
|
|
for(var i=stack.length-2; i>=0; --i) {
|
|
var n = stack[i]
|
|
if(n.left === stack[i+1]) {
|
|
cstack[i] = new RBNode(n._color, n.key, n.value, cstack[i+1], n.right, n._count)
|
|
} else {
|
|
cstack[i] = new RBNode(n._color, n.key, n.value, n.left, cstack[i+1], n._count)
|
|
}
|
|
}
|
|
|
|
//Get node
|
|
n = cstack[cstack.length-1]
|
|
//console.log("start remove: ", n.value)
|
|
|
|
//If not leaf, then swap with previous node
|
|
if(n.left && n.right) {
|
|
//console.log("moving to leaf")
|
|
|
|
//First walk to previous leaf
|
|
var split = cstack.length
|
|
n = n.left
|
|
while(n.right) {
|
|
cstack.push(n)
|
|
n = n.right
|
|
}
|
|
//Copy path to leaf
|
|
var v = cstack[split-1]
|
|
cstack.push(new RBNode(n._color, v.key, v.value, n.left, n.right, n._count))
|
|
cstack[split-1].key = n.key
|
|
cstack[split-1].value = n.value
|
|
|
|
//Fix up stack
|
|
for(var i=cstack.length-2; i>=split; --i) {
|
|
n = cstack[i]
|
|
cstack[i] = new RBNode(n._color, n.key, n.value, n.left, cstack[i+1], n._count)
|
|
}
|
|
cstack[split-1].left = cstack[split]
|
|
}
|
|
//console.log("stack=", cstack.map(function(v) { return v.value }))
|
|
|
|
//Remove leaf node
|
|
n = cstack[cstack.length-1]
|
|
if(n._color === RED) {
|
|
//Easy case: removing red leaf
|
|
//console.log("RED leaf")
|
|
var p = cstack[cstack.length-2]
|
|
if(p.left === n) {
|
|
p.left = null
|
|
} else if(p.right === n) {
|
|
p.right = null
|
|
}
|
|
cstack.pop()
|
|
for(var i=0; i<cstack.length; ++i) {
|
|
cstack[i]._count--
|
|
}
|
|
return new RedBlackTree(this.tree._compare, cstack[0])
|
|
} else {
|
|
if(n.left || n.right) {
|
|
//Second easy case: Single child black parent
|
|
//console.log("BLACK single child")
|
|
if(n.left) {
|
|
swapNode(n, n.left)
|
|
} else if(n.right) {
|
|
swapNode(n, n.right)
|
|
}
|
|
//Child must be red, so repaint it black to balance color
|
|
n._color = BLACK
|
|
for(var i=0; i<cstack.length-1; ++i) {
|
|
cstack[i]._count--
|
|
}
|
|
return new RedBlackTree(this.tree._compare, cstack[0])
|
|
} else if(cstack.length === 1) {
|
|
//Third easy case: root
|
|
//console.log("ROOT")
|
|
return new RedBlackTree(this.tree._compare, null)
|
|
} else {
|
|
//Hard case: Repaint n, and then do some nasty stuff
|
|
//console.log("BLACK leaf no children")
|
|
for(var i=0; i<cstack.length; ++i) {
|
|
cstack[i]._count--
|
|
}
|
|
var parent = cstack[cstack.length-2]
|
|
fixDoubleBlack(cstack)
|
|
//Fix up links
|
|
if(parent.left === n) {
|
|
parent.left = null
|
|
} else {
|
|
parent.right = null
|
|
}
|
|
}
|
|
}
|
|
return new RedBlackTree(this.tree._compare, cstack[0])
|
|
}
|
|
|
|
//Returns key
|
|
Object.defineProperty(iproto, "key", {
|
|
get: function() {
|
|
if(this._stack.length > 0) {
|
|
return this._stack[this._stack.length-1].key
|
|
}
|
|
return
|
|
},
|
|
enumerable: true
|
|
})
|
|
|
|
//Returns value
|
|
Object.defineProperty(iproto, "value", {
|
|
get: function() {
|
|
if(this._stack.length > 0) {
|
|
return this._stack[this._stack.length-1].value
|
|
}
|
|
return
|
|
},
|
|
enumerable: true
|
|
})
|
|
|
|
|
|
//Returns the position of this iterator in the sorted list
|
|
Object.defineProperty(iproto, "index", {
|
|
get: function() {
|
|
var idx = 0
|
|
var stack = this._stack
|
|
if(stack.length === 0) {
|
|
var r = this.tree.root
|
|
if(r) {
|
|
return r._count
|
|
}
|
|
return 0
|
|
} else if(stack[stack.length-1].left) {
|
|
idx = stack[stack.length-1].left._count
|
|
}
|
|
for(var s=stack.length-2; s>=0; --s) {
|
|
if(stack[s+1] === stack[s].right) {
|
|
++idx
|
|
if(stack[s].left) {
|
|
idx += stack[s].left._count
|
|
}
|
|
}
|
|
}
|
|
return idx
|
|
},
|
|
enumerable: true
|
|
})
|
|
|
|
//Advances iterator to next element in list
|
|
iproto.next = function() {
|
|
var stack = this._stack
|
|
if(stack.length === 0) {
|
|
return
|
|
}
|
|
var n = stack[stack.length-1]
|
|
if(n.right) {
|
|
n = n.right
|
|
while(n) {
|
|
stack.push(n)
|
|
n = n.left
|
|
}
|
|
} else {
|
|
stack.pop()
|
|
while(stack.length > 0 && stack[stack.length-1].right === n) {
|
|
n = stack[stack.length-1]
|
|
stack.pop()
|
|
}
|
|
}
|
|
}
|
|
|
|
//Checks if iterator is at end of tree
|
|
Object.defineProperty(iproto, "hasNext", {
|
|
get: function() {
|
|
var stack = this._stack
|
|
if(stack.length === 0) {
|
|
return false
|
|
}
|
|
if(stack[stack.length-1].right) {
|
|
return true
|
|
}
|
|
for(var s=stack.length-1; s>0; --s) {
|
|
if(stack[s-1].left === stack[s]) {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
})
|
|
|
|
//Update value
|
|
iproto.update = function(value) {
|
|
var stack = this._stack
|
|
if(stack.length === 0) {
|
|
throw new Error("Can't update empty node!")
|
|
}
|
|
var cstack = new Array(stack.length)
|
|
var n = stack[stack.length-1]
|
|
cstack[cstack.length-1] = new RBNode(n._color, n.key, value, n.left, n.right, n._count)
|
|
for(var i=stack.length-2; i>=0; --i) {
|
|
n = stack[i]
|
|
if(n.left === stack[i+1]) {
|
|
cstack[i] = new RBNode(n._color, n.key, n.value, cstack[i+1], n.right, n._count)
|
|
} else {
|
|
cstack[i] = new RBNode(n._color, n.key, n.value, n.left, cstack[i+1], n._count)
|
|
}
|
|
}
|
|
return new RedBlackTree(this.tree._compare, cstack[0])
|
|
}
|
|
|
|
//Moves iterator backward one element
|
|
iproto.prev = function() {
|
|
var stack = this._stack
|
|
if(stack.length === 0) {
|
|
return
|
|
}
|
|
var n = stack[stack.length-1]
|
|
if(n.left) {
|
|
n = n.left
|
|
while(n) {
|
|
stack.push(n)
|
|
n = n.right
|
|
}
|
|
} else {
|
|
stack.pop()
|
|
while(stack.length > 0 && stack[stack.length-1].left === n) {
|
|
n = stack[stack.length-1]
|
|
stack.pop()
|
|
}
|
|
}
|
|
}
|
|
|
|
//Checks if iterator is at start of tree
|
|
Object.defineProperty(iproto, "hasPrev", {
|
|
get: function() {
|
|
var stack = this._stack
|
|
if(stack.length === 0) {
|
|
return false
|
|
}
|
|
if(stack[stack.length-1].left) {
|
|
return true
|
|
}
|
|
for(var s=stack.length-1; s>0; --s) {
|
|
if(stack[s-1].right === stack[s]) {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
})
|
|
|
|
//Default comparison function
|
|
function defaultCompare(a, b) {
|
|
if(a < b) {
|
|
return -1
|
|
}
|
|
if(a > b) {
|
|
return 1
|
|
}
|
|
return 0
|
|
}
|
|
|
|
//Build a tree
|
|
function createRBTree(compare) {
|
|
return new RedBlackTree(compare || defaultCompare, null)
|
|
} |