A greeting tree.
using the red-black tree implemented by Mikola Lysenko:
github.com/mikolalysenko/functional-red-black-tree
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// You can find the Turtle API reference here: https://turtletoy.net/syntax
Canvas.setpenopacity(-0.6);
const TOP = -100;
const BOTTOM = 100
const LEFT = -100;
const RIGHT = 100;
const CANVAS_SIZE = BOTTOM - TOP;
const TEXT_SIZE = 0.15;
const DEPTH_OFFSET = 27;
const CHILD_OFFEST = 95.0;
const VALUE_RANGE = 100;
//const NUM_NODES = 24;
const ROOT_NODE_OFFESET = 75;
let WORDS = "FRIENDDOYOUNEEDAHUG?";
const NODE_RADIUS = 5;
const turtle = new Turtle(-25,-5);
////////////////////////////////////////////////////////////////
// Text utility code. Created by Reinder Nijhoff 2019
// https://turtletoy.net/turtle/1713ddbe99
////////////////////////////////////////////////////////////////
function Text() {
class Text {
print (t, str, scale = 1, italic = 0, kerning = 1) {
t.radians();
let pos = [t.x(), t.y()], h = t.h(), o = pos;
str.split('').map(c => {
const i = c.charCodeAt(0) - 32;
if (i < 0 ) {
pos = o = this.rotAdd([0, 48*scale], o, h);
} else if (i > 96 ) {
pos = this.rotAdd([16*scale, 0], o, h);
} else {
const d = dat[i], lt = d[0]*scale, rt = d[1]*scale, paths = d[2];
paths.map( p => {
t.up();
p.map( s=> {
t.goto(this.rotAdd([(s[0]-s[1]*italic)*scale - lt, s[1]*scale], pos, h));
t.down();
});
});
pos = this.rotAdd([(rt - lt)*kerning, 0], pos, h);
}
});
}
rotAdd (a, b, h) {
return [Math.cos(h)*a[0] - Math.sin(h)*a[1] + b[0],
Math.cos(h)*a[1] + Math.sin(h)*a[0] + b[1]];
}
}
const dat = ('br>eoj^jl<jqirjskrjq>brf^fe<n^ne>`ukZdz<qZjz<dgrg<cmqm>`thZhw<lZlw<qao_l^h^e_caccdeefg'+
'gmiojpkqmqporlshsercp>^vs^as<f^h`hbgdeeceacaab_d^f^h_k`n`q_s^<olmmlolqnspsrrspsnqlol>]wtgtfsereqfph'+
'nmlpjrhsdsbraq`o`makbjifjekckaj_h^f_eaecffhimporqssstrtq>eoj`i_j^k_kajcid>cqnZl\\j_hcghglhqjulxnz>c'+
'qfZh\\j_lcmhmllqjuhxfz>brjdjp<egom<ogem>]wjajs<ajsj>fnkojpiojnkokqis>]wajsj>fnjniojpkojn>_usZaz>`ti'+
'^f_dbcgcjdofrisksnrpoqjqgpbn_k^i^>`tfbhak^ks>`tdcdbe`f_h^l^n_o`pbpdofmicsqs>`te^p^jfmfogphqkqmppnrk'+
'shserdqco>`tm^clrl<m^ms>`to^e^dgefhekenfphqkqmppnrkshserdqco>`tpao_l^j^g_ebdgdlepgrjsksnrppqmqlping'+
'kfjfggeidl>`tq^gs<c^q^>`th^e_dadceegfkgnhpjqlqopqorlshserdqcocldjfhigmfoepcpao_l^h^>`tpeohmjjkikfjd'+
'hcecddaf_i^j^m_oapepjoomrjshserdp>fnjgihjikhjg<jniojpkojn>fnjgihjikhjg<kojpiojnkokqis>^vrabjrs>]wag'+
'sg<amsm>^vbarjbs>asdcdbe`f_h^l^n_o`pbpdofngjijl<jqirjskrjq>]xofndlcicgdfeehekfmhnknmmnk<icgefhfkgmh'+
'n<ocnknmpnrntluiugtdsbq`o_l^i^f_d`bbad`g`jambodqfrislsorqqrp<pcokompn>asj^bs<j^rs<elol>_tc^cs<c^l^o'+
'_p`qbqdpfoglh<chlhoipjqlqopqorlscs>`urcqao_m^i^g_eadccfckdnepgrismsorqprn>_tc^cs<c^j^m_oapcqfqkpnop'+
'mrjscs>`sd^ds<d^q^<dhlh<dsqs>`rd^ds<d^q^<dhlh>`urcqao_m^i^g_eadccfckdnepgrismsorqprnrk<mkrk>_uc^cs<'+
'q^qs<chqh>fnj^js>brn^nnmqlrjshsfreqdndl>_tc^cs<q^cl<hgqs>`qd^ds<dsps>^vb^bs<b^js<r^js<r^rs>_uc^cs<c'+
'^qs<q^qs>_uh^f_daccbfbkcndpfrhslsnrppqnrkrfqcpan_l^h^>_tc^cs<c^l^o_p`qbqepgohlici>_uh^f_daccbfbkcnd'+
'pfrhslsnrppqnrkrfqcpan_l^h^<koqu>_tc^cs<c^l^o_p`qbqdpfoglhch<jhqs>`tqao_l^h^e_caccdeefggmiojpkqmqpo'+
'rlshsercp>brj^js<c^q^>_uc^cmdpfrisksnrppqmq^>asb^js<r^js>^v`^es<j^es<j^os<t^os>`tc^qs<q^cs>asb^jhjs'+
'<r^jh>`tq^cs<c^q^<csqs>cqgZgz<hZhz<gZnZ<gznz>cqc^qv>cqlZlz<mZmz<fZmZ<fzmz>brj\\bj<j\\rj>asazsz>fnkc'+
'ieigjhkgjfig>atpeps<phnfleiegfehdkdmepgrislsnrpp>`sd^ds<dhffhekemfohpkpmopmrkshsfrdp>asphnfleiegfeh'+
'dkdmepgrislsnrpp>atp^ps<phnfleiegfehdkdmepgrislsnrpp>asdkpkpiognfleiegfehdkdmepgrislsnrpp>eqo^m^k_j'+
'bjs<gene>atpepuoxnylzizgy<phnfleiegfehdkdmepgrislsnrpp>ate^es<eihfjemeofpips>fni^j_k^j]i^<jejs>eoj^'+
'k_l^k]j^<kekvjyhzfz>are^es<oeeo<ikps>fnj^js>[y_e_s<_ibfdegeifjijs<jimfoeretfuius>ateees<eihfjemeofp'+
'ips>atiegfehdkdmepgrislsnrppqmqkphnfleie>`sdedz<dhffhekemfohpkpmopmrkshsfrdp>atpepz<phnfleiegfehdkd'+
'mepgrislsnrpp>cpgegs<gkhhjfleoe>bsphofleieffehfjhkmlompopporlsisfrep>eqj^jokrmsos<gene>ateeeofrhsks'+
'mrpo<peps>brdejs<pejs>_ubefs<jefs<jens<rens>bseeps<pees>brdejs<pejshwfydzcz>bspees<eepe<esps>cqlZj['+
'i\\h^h`ibjckekgii<j[i]i_jakbldlfkhgjkllnlpkrjsiuiwjy<ikkmkojqirhthvixjylz>fnjZjz>cqhZj[k\\l^l`kbjci'+
'eigki<j[k]k_jaibhdhfihmjilhnhpirjskukwjy<kkimiojqkrltlvkxjyhz>^vamakbhdgfghhlknlplrksi<akbidhfhhill'+
'nmpmrlsisg>brb^bscsc^d^dsese^f^fsgsg^h^hsisi^j^jsksk^l^lsmsm^n^nsoso^p^psqsq^r^rs').split('>').map(
r=> { return [r.charCodeAt(0)-106,r.charCodeAt(1)-106, r.substr(2).split('<').map(a => {const ret
= []; for (let i=0; i<a.length; i+=2) {ret.push(a.substr(i, 2).split('').map(b => b.charCodeAt(0)
-106));} return ret; })]; });
return new Text();
}
const txt = new Text();
// drawing utilities
function circle(x,y,radius,extent=undefined){turtle.penup();turtle.goto(x,y-radius);turtle.pendown();turtle.circle(radius,extent);}
function line(x1,y1,x2,y2){turtle.penup();turtle.goto(x1,y1);turtle.pendown();turtle.goto(x2,y2);}
function rect(l,t,b,r){line(l,t,l,b);line(l,t,r,t);line(r,t,r,b);line(l,b,r,b);}
function text(x,y,content,size){turtle.penup();turtle.goto(x,y-size);turtle.pendown();txt.print(turtle, content, size);}
function line1(x1,y1,x2,y2,radius){
turtle.penup();
ratio = radius/Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
dx = ratio*(x2-x1);
dy = ratio*(y2-y1);
turtle.goto(x1+dx,y1+dy);
turtle.pendown();
turtle.goto(x2-dx,y2-dy);
}
// Red black tree
// https://github.com/mikolalysenko/functional-red-black-tree/blob/master/rbtree.js
/*
The MIT License (MIT)
Copyright (c) 2013 Mikola Lysenko
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
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)
}
// node color
// const BLACK = 0;
// const RED = 1;
function DrawNodeInternal(x,y,color,txt)
{
circle(x,y,NODE_RADIUS)
//circle(x+0.2,y+0.2,NODE_RADIUS)
//circle(x-0.2,y-0.2,NODE_RADIUS)
if(txt)
{
const final_txt = ""+txt;
for(var i=0;i<20;i++)
{
text(x-1.5,y+0.1,final_txt, TEXT_SIZE);//
}
}
if(!color)return;
//circle(x,y,NODE_RADIUS*1.1)
//circle(x,y,NODE_RADIUS*0.9)
//circle(x,y,NODE_RADIUS*0.8)
//for(var i=0;i<NODE_RADIUS;i+=0.1){circle(x,y,i);}
}
const DepthOffset = DEPTH_OFFSET;
const ChildOffset = CHILD_OFFEST;
function DrawTreeNode(node,x,y,depth)
{
if(node)
{
DrawNodeInternal(x,y,node._color,node.value);
}
else
{
return;
}
// recursively draw children
depth++;
const y1 = y+DepthOffset;
const xOffset = ChildOffset*Math.pow(0.5,depth);
if(node.left)
{
const x1 = x-xOffset///depth;
for(var i=0;i<5;i++)
{
line1(x,y,x1,y1,NODE_RADIUS*1.1);
}
DrawTreeNode(node.left,x1,y1,depth);
}
if(node.right)
{
const x1 = x+xOffset///depth;
for(var i=0;i<5;i++)
{
line1(x,y-2,x1,y1,NODE_RADIUS*1.5);
}
DrawTreeNode(node.right,x1,y1,depth);
}
}
function GenerateRBTree()
{
//Create a tree
var testTree = createRBTree()
//Insert some items into the tree
for(var i=0;i<WORDS.length;i++)
{
//testTree = testTree.insert(Math.floor(Math.random() * VALUE_RANGE));
testTree = testTree.insert(i,WORDS[i]);
}
DrawTreeNode(testTree.root,0,-ROOT_NODE_OFFESET,0);
}
GenerateRBTree();
// draw title
for(var i=0;i<5;i++)
{
text(-95,94,"A 'greeting' tree.", 0.15);
}
// The walk function will be called until it returns false.
function walk(i) {
return i < 1;
}