Visualize a tree: Difference between revisions
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Using the same tree structure (including tree node constructor and accessors) as in the [[Tree_traversal|Tree Traversal]] task, and centering parent nodes vertically: |
Using the same tree structure (including tree node constructor and accessors) as in the [[Tree_traversal|Tree Traversal]] task, and centering parent nodes vertically: |
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Or drawing a simpler (decorated-outline tree): |
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{{Works with|Python|3}} |
{{Works with|Python|3}} |
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Revision as of 21:48, 21 June 2019
You are encouraged to solve this task according to the task description, using any language you may know.
A tree structure (i.e. a rooted, connected acyclic graph) is often used in programming.
It's often helpful to visually examine such a structure.
There are many ways to represent trees to a reader, such as:
- indented text (à la unix
treecommand) - nested HTML tables
- hierarchical GUI widgets
- 2D or 3D images
- etc.
- indented text (à la unix
- Task
Write a program to produce a visual representation of some tree.
The content of the tree doesn't matter, nor does the output format, the only requirement being that the output is human friendly.
Make do with the vague term "friendly" the best you can.
11l
<lang 11l>T Node
String value Node? left Node? right
F (value, Node? left = N, Node? right = N)
.value = String(value)
.left = left
.right = right
F tree_indent() -> [String]
V tr = I .right != N {.right.tree_indent()} E [‘-- (null)’]
R [‘--’(.value)] [+] (I .left != N {.left.tree_indent()} E [‘-- (null)’]).map(a -> ‘ |’a)
[+] [‘ `’tr[0]] + tr[1..].map(a -> ‘ ’a)
V tree = Node(1, Node(2, Node(4, Node(7)), Node(5)), Node(3, Node(6, Node(8), Node(9)))) print(tree.tree_indent().join("\n"))</lang>
Ada
Prints a tree of the current directory. <lang Ada>with Ada.Text_IO, Ada.Directories;
procedure Directory_Tree is
procedure Print_Tree(Current: String; Indention: Natural := 0) is
function Spaces(N: Natural) return String is
(if N= 0 then "" else " " & Spaces(N-1));
use Ada.Directories;
Search: Search_Type;
Found: Directory_Entry_Type;
begin
Start_Search(Search, Current, "");
while More_Entries(Search) loop
Get_Next_Entry(Search, Found); declare Name: String := Simple_Name(Found); Dir: Boolean := Kind(Found) = Directory; begin if Name(Name'First) /= '.' then
-- skip all files who's names start with ".", namely "." and ".."
Ada.Text_IO.Put_Line(Spaces(2*Indention) & Simple_Name(Found) & (if Dir then " (dir)" else "")); if Dir then Print_Tree(Full_Name(Found), Indention + 1); end if; end if; end;
end loop; end Print_Tree;
begin
Print_Tree(Ada.Directories.Current_Directory);
end Directory_Tree;</lang>
- Output:
outer (dir)
inner (dir)
innermost (dir)
file
another
file
some
ALGOL 68
<lang algol68># outputs nested html tables to visualise a tree #
- mode representing nodes of the tree #
MODE NODE = STRUCT( STRING value, REF NODE child, REF NODE sibling ); REF NODE nil node = NIL;
- tags etc. #
STRING table = "
" , elbat = "" , tr = "" , rt = "" , td = "<td style=""text-align: center; vertical-align: top; """ , dt = "" , nbsp = " " ; CHAR nl = REPR 10;
- returns the number of child elements of tree #
OP CHILDCOUNT = ( REF NODE tree )INT: BEGIN INT result := 0; REF NODE child := child OF tree; WHILE REF NODE( child ) ISNT nil node DO result +:= 1; child := sibling OF child OD; result END # CHILDCOUNT # ;
- generates nested HTML tables from the tree #
OP TOHTML = ( REF NODE tree )STRING: IF tree IS nil node THEN # no node # "" ELSE # hae at least one node # STRING result := ""; INT child count = CHILDCOUNT tree; result +:= table + nl + tr + nl + td + " colspan=""" + whole( IF child count < 1 THEN 1 ELSE child count FI, 0 ) + """>" + nbsp + value OF tree + nbsp + dt + nl + rt + nl ; IF child count > 0 THEN # the node has branches # REF NODE child := child OF tree; INT child number := 1; INT mid child = ( child count + 1 ) OVER 2; child := child OF tree; result +:= tr + nl; WHILE child ISNT nil node DO result +:= td + ">" + nl + IF CHILDCOUNT child < 1 THEN nbsp + value OF child + nbsp ELSE TOHTML child FI + dt + nl; child := sibling OF child OD; result +:= rt + nl FI; result +:= elbat + nl FI # TOHTML # ;
- test the tree visualisation #
- returns a new node with the specified value and no child or siblings #
PROC new node = ( STRING value )REF NODE: HEAP NODE := NODE( value, nil node, nil node );
- appends a sibling node to the node n, returns the sibling #
OP +:= = ( REF NODE n, REF NODE sibling node )REF NODE: BEGIN REF NODE sibling := n; WHILE REF NODE( sibling OF sibling ) ISNT nil node DO sibling := sibling OF sibling OD; sibling OF sibling := sibling node END # +:= # ;
- appends a new sibling node to the node n, returns the sibling #
OP +:= = ( REF NODE n, STRING sibling value )REF NODE: n +:= new node( sibling value );
- adds a child node to the node n, returns the child #
OP /:= = ( REF NODE n, REF NODE child node )REF NODE: child OF n := child node;
- adda a new child node to the node n, returns the child #
OP /:= = ( REF NODE n, STRING child value )REF NODE: n /:= new node( child value ); NODE animals := new node( "animals" ); NODE fish := new node( "fish" ); NODE reptiles := new node( "reptiles" ); NODE mammals := new node( "mammals" ); NODE primates := new node( "primates" ); NODE sharks := new node( "sharks" ); sharks /:= "great-white" +:= "hammer-head"; fish /:= "cod" +:= sharks +:= "piranha"; reptiles /:= "iguana" +:= "brontosaurus"; primates /:= "gorilla" +:= "lemur"; mammals /:= "sloth" +:= "horse" +:= "bison" +:= primates; animals /:= fish +:= reptiles +:= mammals; print( ( TOHTML animals ) )</lang>
- Output:
| animals | ||||||||||||||||||||||||||||
|
|
|
||||||||||||||||||||||||||
Batch File
Prints a tree of the current directory. <lang dos>@tree %cd%</lang>
BBC BASIC
This creates a native Windows Tree View control: <lang bbcbasic> INSTALL @lib$+"WINLIB5"
ON ERROR SYS "MessageBox", @hwnd%, REPORT$, 0, 0 : QUIT
REM!WC Windows constants:
TVI_SORT = -65533
TVIF_TEXT = 1
TVM_INSERTITEM = 4352
TVS_HASBUTTONS = 1
TVS_HASLINES = 2
TVS_LINESATROOT = 4
REM. TV_INSERTSTRUCT
DIM tvi{hParent%, \
\ hInsertAfter%, \
\ mask%, \
\ hItem%, \
\ state%, \
\ stateMask%, \
\ pszText%, \
\ cchTextMax%, \
\ iImage%, \
\ iSelectedImage%,\
\ cChildren%, \
\ lParam% \
\ }
SYS "InitCommonControls"
hTree% = FN_createwindow("SysTreeView32", "", 0, 0, @vdu.tr%, @vdu.tb%, 0, \
\ TVS_HASLINES OR TVS_HASBUTTONS OR TVS_LINESATROOT, 0)
hroot% = FNinsertnode(0, "Root")
hchild1% = FNinsertnode(hroot%, "Child 1")
hchild2% = FNinsertnode(hroot%, "Child 2")
hchild11% = FNinsertnode(hchild1%, "Grandchild 1")
hchild12% = FNinsertnode(hchild1%, "Grandchild 2")
hchild21% = FNinsertnode(hchild2%, "Grandchild 3")
hchild22% = FNinsertnode(hchild2%, "Grandchild 4")
REPEAT
WAIT 1
UNTIL FALSE
END
DEF FNinsertnode(hparent%, text$)
LOCAL hnode%
text$ += CHR$0
tvi.hParent% = hparent%
tvi.hInsertAfter% = TVI_SORT
tvi.mask% = TVIF_TEXT
tvi.pszText% = !^text$
SYS "SendMessage", hTree%, TVM_INSERTITEM, 0, tvi{} TO hnode%
IF hnode% = 0 ERROR 100, "TVM_INSERTITEM failed"
SYS "InvalidateRect", hTree%, 0, 0
= hnode%</lang>
C
Print a simple tree to standard output: <lang c>#include <stdio.h>
- include <stdlib.h>
typedef struct stem_t *stem; struct stem_t { const char *str; stem next; };
void tree(int root, stem head) { static const char *sdown = " |", *slast = " `", *snone = " "; struct stem_t col = {0, 0}, *tail;
for (tail = head; tail; tail = tail->next) { printf("%s", tail->str); if (!tail->next) break; }
printf("--%d\n", root);
if (root <= 1) return;
if (tail && tail->str == slast) tail->str = snone;
if (!tail) tail = head = &col; else tail->next = &col;
while (root) { // make a tree by doing something random int r = 1 + (rand() % root); root -= r; col.str = root ? sdown : slast;
tree(r, head); }
tail->next = 0; }
int main(int c, char**v) { int n; if (c < 2 || (n = atoi(v[1])) < 0) n = 8;
tree(n, 0); return 0; }</lang>
- Output:
--8
`--8
|--7
| |--3
| | |--2
| | | `--2
| | | `--2
| | | |--1
| | | `--1
| | `--1
| |--2
| | |--1
| | `--1
| |--1
| `--1
`--1
Clojure
<lang clojure>(use 'vijual)
(draw-tree [[:A] [:B] [:C [:D [:E] [:F]] [:G]]]) </lang>
- Output:
+---+ +---+ +---+
| A | | B | | C |
+---+ +---+ +-+-+
|
+-----+
| |
+-+-+ +-+-+
| D | | G |
+-+-+ +---+
|
+--+--+
| |
+-+-+ +-+-+
| E | | F |
+---+ +---+
Common Lisp
<lang lisp>(defun visualize (tree)
(labels
((rprint (list)
(mapc #'princ (reverse list)))
(vis-h (tree branches)
(let ((len (length tree)))
(loop
for item in tree
for idx from 1 to len do
(cond
((listp item)
(rprint (cdr branches))
(princ "+---+")
(let ((next (cons "| "
(if (= idx len)
(cons " " (cdr branches))
branches))))
(terpri)
(rprint (if (null item)
(cdr next)
next))
(terpri)
(vis-h item next)))
(t
(rprint (cdr branches))
(princ item)
(terpri)
(rprint (if (= idx len)
(cdr branches)
branches))
(terpri)))))))
(vis-h tree '("| "))))</lang>
- Output:
<lang lisp>CL-USER> (visualize '(a b c ((d (e ((() ()))) f)) (g))) A | B | C | +---+ | | | +---+ | | | D | | | +---+ | | | | | E | | | | | +---+ | | | | | +---+ | | | | | +---+ | | | | | +---+ | | | F | +---+
| G
NIL</lang>
D
<lang d>import std.stdio, std.conv, std.algorithm, std.array;
struct Node(T) { T value; Node* left, right; }
string[] treeIndent(T)(in Node!T* t) pure nothrow @safe {
if (!t) return ["-- (null)"];
const tr = t.right.treeIndent;
return "--" ~ t.value.text ~
t.left.treeIndent.map!q{" |" ~ a}.array ~
(" `" ~ tr[0]) ~ tr[1 .. $].map!q{" " ~ a}.array;
}
void main () {
static N(T)(T v, Node!T* l=null, Node!T* r=null) {
return new Node!T(v, l, r);
}
const tree = N(1, N(2, N(4, N(7)), N(5)), N(3, N(6, N(8), N(9))));
writefln("%-(%s\n%)", tree.treeIndent);
}</lang>
- Output:
--1
|--2
| |--4
| | |--7
| | | |-- (null)
| | | `-- (null)
| | `-- (null)
| `--5
| |-- (null)
| `-- (null)
`--3
|--6
| |--8
| | |-- (null)
| | `-- (null)
| `--9
| |-- (null)
| `-- (null)
`-- (null)
Elena
ELENA 4.x : <lang elena>import system'routines; import extensions;
class Node {
string theValue;
Node[] theChildren;
constructor new(string value, Node[] children)
{
theValue := value;
theChildren := children;
}
constructor new(string value)
<= new(value, new Node[](0));
constructor new(Node[] children)
<= new(emptyString, children);
get() = theValue;
Children = theChildren;
}
extension treeOp {
writeTree(node, prefix)
{
var children := node.Children;
var length := children.Length;
children.zipForEach(new Range(1, length), (child,index)
{
self.printLine(prefix,"|");
self.printLine(prefix,"+---",child.get());
var nodeLine := prefix + (index==length).iif(" ","| ");
self.writeTree(child,nodeLine);
});
^ self
}
writeTree(node)
= self.writeTree(node,"");
}
public program() {
var tree := Node.new(
new Node[]{
Node.new("a", new Node[]
{
Node.new("b", new Node[]{Node.new("c")}),
Node.new("d")
}),
Node.new("e")
});
console.writeTree(tree).readChar()
}</lang>
- Output:
| +---a | | | +---b | | | | | +---c | | | +---d | +---b
Erlang
Until real code shows up, I follow the lead of Python and print tuples with a width of 1.
- Output:
9> io:fwrite("~1p", [{1, 2, {30, 40}, {{500, 600}, 70}}]).
{1,
2,
{30,
40},
{{500,
600},
70}}
F#
<lang fsharp>type tree =
| T of string * tree list
let prefMid = seq { yield "├─"; while true do yield "│ " } let prefEnd = seq { yield "└─"; while true do yield " " } let prefNone = seq { while true do yield "" }
let c2 x y = Seq.map2 (fun u v -> String.concat "" [u; v]) x y
let rec visualize (T(label, children)) pre =
seq {
yield (Seq.head pre) + label
if children <> [] then
let preRest = Seq.skip 1 pre
let last = Seq.last (List.toSeq children)
for e in children do
if e = last then yield! visualize e (c2 preRest prefEnd)
else yield! visualize e (c2 preRest prefMid)
}
let example =
T ("root",
[T ("a",
[T ("a1",
[T ("a11", []);
T ("a12", []) ]) ]);
T ("b",
[T ("b1", []) ]) ])
visualize example prefNone |> Seq.iter (printfn "%s")</lang>
- Output:
root ├─a │ └─a1 │ ├─a11 │ └─a12 └─b └─b1
Factor
Factor's prettyprinter does this by default with any nested sequences and/or tuples. There are dynamic variables that can be altered to change the prettyprinter's default behavior. The most interesting are tab-size and margin for customizing the look of a tree. For smaller trees, it's best to change margin from its default of 64 to something low, perhaps 10.
<lang factor>USE: literals
CONSTANT: mammals { "mammals" { "deer" "gorilla" "dolphin" } } CONSTANT: reptiles { "reptiles" { "turtle" "lizard" "snake" } }
{ "animals" ${ mammals reptiles } } dup . 10 margin set .</lang>
- Output:
{
"animals"
{
{ "mammals" { "deer" "gorilla" "dolphin" } }
{ "reptiles" { "turtle" "lizard" "snake" } }
}
}
{
"animals"
{
{
"mammals"
{
"deer"
"gorilla"
"dolphin"
}
}
{
"reptiles"
{
"turtle"
"lizard"
"snake"
}
}
}
}
An example showcasing tuples by displaying an AVL tree: <lang factor>USE: trees.avl AVL{ { 1 2 } { 9 19 } { 3 4 } { 5 6 } } .</lang>
- Output:
T{ avl
{ root
T{ avl-node
{ key 3 }
{ value 4 }
{ left
T{ avl-node
{ key 1 }
{ value 2 }
{ balance 0 }
}
}
{ right
T{ avl-node
{ key 9 }
{ value 19 }
{ left
T{ avl-node
{ key 5 }
{ value 6 }
{ balance 0 }
}
}
{ balance -1 }
}
}
{ balance 1 }
}
}
{ count 4 }
}
Fōrmulæ
In this page you can see the solution of this task.
Fōrmulæ programs are not textual, visualization/edition of programs is done showing/manipulating structures but not text (more info). Moreover, there can be multiple visual representations of the same program. Even though it is possible to have textual representation —i.e. XML, JSON— they are intended for transportation effects more than visualization and edition.
The option to show Fōrmulæ programs and their results is showing images. Unfortunately images cannot be uploaded in Rosetta Code.
Go
JSON
Not the most economical output, but at least json.MarshalIndent is in the Go standard library. Note that the definition of Node has nothing JSON specific about it; it's an ordinary struct. <lang Go>package main
import (
"encoding/json" "fmt" "log"
)
type Node struct {
Name string Children []*Node
}
func main() {
tree := &Node{"root", []*Node{
&Node{"a", []*Node{
&Node{"d", nil},
&Node{"e", []*Node{
&Node{"f", nil},
}}}},
&Node{"b", nil},
&Node{"c", nil},
}}
b, err := json.MarshalIndent(tree, "", " ")
if err != nil {
log.Fatal(err)
}
fmt.Println(string(b))
}</lang>
- Output:
{
"Name": "root",
"Children": [
{
"Name": "a",
"Children": [
{
"Name": "d",
"Children": null
},
{
"Name": "e",
"Children": [
{
"Name": "f",
"Children": null
}
]
}
]
},
{
"Name": "b",
"Children": null
},
{
"Name": "c",
"Children": null
}
]
}
TOML
It works in this case, but TOML wasn't really designed for this and encoders may have trouble with general trees. Empty trees and nils for example might be problematic depending on your data structures and limitations of your TOML encoder. YMMV. <lang go>package main
import (
"log" "os"
"github.com/BurntSushi/toml"
)
type Node struct {
Name string Children []*Node
}
func main() {
tree := &Node{"root", []*Node{
&Node{"a", []*Node{
&Node{"d", nil},
&Node{"e", []*Node{
&Node{"f", nil},
}}}},
&Node{"b", nil},
&Node{"c", nil},
}}
enc := toml.NewEncoder(os.Stdout)
enc.Indent = " "
err := enc.Encode(tree)
if err != nil {
log.Fatal(err)
}
}</lang>
- Output:
Name = "root"
[[Children]]
Name = "a"
[[Children.Children]]
Name = "d"
[[Children.Children]]
Name = "e"
[[Children.Children.Children]]
Name = "f"
[[Children]]
Name = "b"
[[Children]]
Name = "c"
Unicode
A non-library solution, more like a number of other solutions on this page, and with more compact output. The tree representation here uses integer indexes rather than pointers, which is efficient for representation and computation. A serialization format like JSON or TOML wouldn't see it as a hierarchical structure, but the code here knows to interpret the child ints as node indexes. <lang go>package main
import "fmt"
type tree []node
type node struct {
label string children []int // indexes into tree
}
func main() {
vis(tree{
0: node{"root", []int{1, 2, 3}},
1: node{"ei", []int{4, 5}},
2: node{"bee", nil},
3: node{"si", nil},
4: node{"dee", nil},
5: node{"y", []int{6}},
6: node{"eff", nil},
})
}
func vis(t tree) {
if len(t) == 0 {
fmt.Println("<empty>")
return
}
var f func(int, string)
f = func(n int, pre string) {
ch := t[n].children
if len(ch) == 0 {
fmt.Println("╴", t[n].label)
return
}
fmt.Println("┐", t[n].label)
last := len(ch) - 1
for _, ch := range ch[:last] {
fmt.Print(pre, "├─")
f(ch, pre+"│ ")
}
fmt.Print(pre, "└─")
f(ch[last], pre+" ")
}
f(0, "")
}</lang>
- Output:
┐ root ├─┐ ei │ ├─╴ dee │ └─┐ y │ └─╴ eff ├─╴ bee └─╴ si
Haskell
Tree borrowed from Tree traversal: <lang haskell>data Tree a = Empty | Node { value :: a, left :: Tree a, right :: Tree a } deriving (Show, Eq)
tree = Node 1 (Node 2 (Node 4 (Node 7 Empty Empty) Empty) (Node 5 Empty Empty)) (Node 3 (Node 6 (Node 8 Empty Empty) (Node 9 Empty Empty)) Empty)
treeIndent Empty = ["-- (nil)"] treeIndent t = ["--" ++ show (value t)] ++ map (" |"++) ls ++ (" `" ++ r):map (" "++) rs where (r:rs) = treeIndent$right t ls = treeIndent$left t
main = mapM_ putStrLn $ treeIndent tree</lang>
- Output:
--1
|--2
| |--4
| | |--7
| | | |-- (nil)
| | | `-- (nil)
| | `-- (nil)
| `--5
| |-- (nil)
| `-- (nil)
`--3
|--6
| |--8
| | |-- (nil)
| | `-- (nil)
| `--9
| |-- (nil)
| `-- (nil)
`-- (nil)
The Data.Tree module in the standard (GHC) libraries also includes a drawTree function for multiway (rose) trees of strings.
We can fmap show over our tree of integers to derive a tree of strings, and apply `drawTree` to that.
<lang haskell>import Data.Tree (Tree(..), drawTree)
tree :: Tree Int tree =
Node 1 [ Node 2 [Node 4 [Node 7 []], Node 5 []] , Node 3 [Node 6 [Node 8 [], Node 9 []]] ]
main :: IO () main = (putStrLn . drawTree . fmap show) tree</lang>
- Output:
1
|
+- 2
| |
| +- 4
| | |
| | `- 7
| |
| `- 5
|
`- 3
|
`- 6
|
+- 8
|
`- 9
Icon and Unicon
The following works in both languages. <lang unicon>procedure main(A)
showTree("", " -", [1, [2,[3],[4,[5],[6]],[7,[11]]], [8,[9,[10]]] ])
write()
showTree("", " -", [1, [2,[3,[4]]], [5,[6],[7,[8],[9]],[10]] ])
end
procedure showTree(prefix, lastc, A)
write(prefix, lastc, "--", A[1])
if *A > 1 then {
prefix ||:= if prefix[-1] == "|" then " " else " "
every showTree(prefix||"|", "-", !A[2:2 < *A])
showTree(prefix, "`-", A[*A])
}
end</lang>
Output:
->tree
---1
|---2
| |---3
| |---4
| | |---5
| | `---6
| `---7
| `---11
`---8
`---9
`---10
---1
|---2
| `---3
| `---4
`---5
|---6
|---7
| |---8
| `---9
`---10
->
J
See: j:Essays/Tree Display for tree represented as label pairs.
Or, adapted to the parent index representation of a tree (which allows different nodes to share labels and may also be more convenient for other reasons):
<lang J>BOXC=: 9!:6 NB. box drawing characters EW =: {: BOXC NB. east-west
showtree=: 4 : 0
NB. y is parent index for each node (non-indices for root nodes)
NB. x is label for each node
t=. (<EW,' ') ,@<@,:@,&":&.> x NB. tree fragments
c=. |:(#~ e./@|:);(~.,"0&.>(</. i.@#)) y
while. +./ b=. ({.c)*.//.-.e.~/c do.
i=. b#~.{.c NB. parents whose children are leaves
j=. </./(({.c)e.i)#"1 c NB. leaves grouped by parents
t=. a: (;j)}t i}~ (i{t) subtree&.> j{&.><t
c=. (-.({.c)e.i)#"1 c NB. prune edges to leaves
end.
;([: ,.&.>/ extend&.>)&> t -. a:
)
subtree=: 4 : 0
p=. EW={."1 s=. >{.t=. graft y
(<(>{.x) root p),(<(connect p),.s),}.t
)
graft=: 3 : 0
n=. (-~ >./) #&> y
f=. i.@(,&0)@#&.>@{.&.> y
,&.>/ y ,&> n$&.>f
)
connect=: 3 : 0
b=. (+./\ *. +./\.) y
c=. (b+2*y){' ',9 3 3{BOXC NB. │ NS ├ E
c=. (0{BOXC) (b i. 1)}c NB. ┌ NW
c=. (6{BOXC) (b i: 1)}c NB. └ SW
j=. (b i. 1)+<.-:+/b
EW&(j})^:(1=+/b) c j}~ ((0 3 6 9{BOXC)i.j{c){1 4 7 5{BOXC
)
root=: 4 : 0
j=. k+<.-:1+(y i: 1)-k=. y i. 1
(-j)|.(#y){.x,.,:' ',EW
)
extend=: 3 : '(+./\"1 (y=EW) *. *./\."1 y e. ,EW)}y,:EW' </lang>
Example use:
<lang j> (i.10) showtree _,}.p:inv i.10
┌─ 6
┌─ 1 ─── 3 ─┴─ 7
│ ┌─ 8
─ 0 ─┤ ┌─ 4 ─┴─ 9
└─ 2 ─┴─ 5 </lang>
Java
Minimalist BST that can do nothing except print itself to stdout. <lang java>public class VisualizeTree {
public static void main(String[] args) {
BinarySearchTree tree = new BinarySearchTree();
tree.insert(100);
for (int i = 0; i < 20; i++)
tree.insert((int) (Math.random() * 200));
tree.display();
}
}
class BinarySearchTree {
private Node root;
private class Node {
private int key;
private Node left, right;
Node(int k) {
key = k;
}
}
public boolean insert(int key) {
if (root == null)
root = new Node(key);
else {
Node n = root;
Node parent;
while (true) {
if (n.key == key)
return false;
parent = n;
boolean goLeft = key < n.key;
n = goLeft ? n.left : n.right;
if (n == null) {
if (goLeft) {
parent.left = new Node(key);
} else {
parent.right = new Node(key);
}
break;
}
}
}
return true;
}
public void display() {
final int height = 5, width = 64;
int len = width * height * 2 + 2;
StringBuilder sb = new StringBuilder(len);
for (int i = 1; i <= len; i++)
sb.append(i < len - 2 && i % width == 0 ? "\n" : ' ');
displayR(sb, width / 2, 1, width / 4, width, root, " ");
System.out.println(sb);
}
private void displayR(StringBuilder sb, int c, int r, int d, int w, Node n,
String edge) {
if (n != null) {
displayR(sb, c - d, r + 2, d / 2, w, n.left, " /");
String s = String.valueOf(n.key);
int idx1 = r * w + c - (s.length() + 1) / 2;
int idx2 = idx1 + s.length();
int idx3 = idx1 - w;
if (idx2 < sb.length())
sb.replace(idx1, idx2, s).replace(idx3, idx3 + 2, edge);
displayR(sb, c + d, r + 2, d / 2, w, n.right, "\\ ");
}
}
}</lang>
100
/ \
49 106
/ \ / \
44 94 105 152
/ \ / / \
26 47 61 109 178
/ \ / \ \ /
12 33 51 88 119 159
JavaScript
HTML
Javascript wrapped in HTML5 document. Should work in modern browsers. <lang html><!doctype html> <html id="doc">
<head><meta charset="utf-8"/> <title>Stuff</title> <script type="application/javascript">
function gid(id) { return document.getElementById(id); }
function ce(tag, cls, parent_node) { var e = document.createElement(tag); e.className = cls; if (parent_node) parent_node.appendChild(e); return e; }
function dom_tree(id) { gid('tree').textContent = ""; gid('tree').appendChild(mktree(gid(id), null)); }
function mktree(e, p) { var t = ce("div", "tree", p); var tog = ce("span", "toggle", t); var h = ce("span", "tag", t);
if (e.tagName === undefined) { h.textContent = "#Text"; var txt = e.textContent; if (txt.length > 0 && txt.match(/\S/)) { h = ce("div", "txt", t); h.textContent = txt; } return t; }
tog.textContent = "−"; tog.onclick = function () { clicked(tog); } h.textContent = e.nodeName;
var l = e.childNodes; for (var i = 0; i != l.length; i++) mktree(l[i], t); return t; }
function clicked(e) { var is_on = e.textContent == "−"; e.textContent = is_on ? "+" : "−"; e.parentNode.className = is_on ? "tree-hide" : "tree"; }
</script>
<style>
#tree { white-space: pre; font-family: monospace; border: 1px solid }
.tree > .tree-hide, .tree > .tree
{ margin-left: 2em; border-left: 1px dotted rgba(0,0,0,.2)}
.tree-hide > .tree, .tree-hide > .tree-hide { display: none }
.tag { color: navy }
.tree-hide > .tag { color: maroon }
.txt { color: gray; padding: 0 .5em; margin: 0 .5em 0 2em; border: 1px dotted rgba(0,0,0,.1) }
.toggle { display: inline-block; width: 2em; text-align: center }
</style>
</head>
<body>
<article>
Headline
Blah blah
More headline
Something something
<section>
Nested section
Somethin somethin list:
- Apples
- Oranges
- Cetera Fruits
</section> </article>
</body>
</html></lang>
Plain text
<lang JavaScript>(() => {
'use strict';
const main = () =>
drawTree(dctTree);
// draw :: Tree String -> [String]
const draw = node => {
// shift :: String -> String -> [String] -> [String]
const shift = (first, other, xs) =>
zipWith(
append,
cons(first, replicate(xs.length - 1, other)),
xs
);
// drawSubTrees :: [Tree String] -> [String]
const drawSubTrees = xs => {
const lng = xs.length;
return 0 < lng ? (
1 < lng ? append(
cons(
'│',
shift('├─ ', '│ ', draw(xs[0]))
),
drawSubTrees(xs.slice(1))
) : cons('│', shift('└─ ', ' ', draw(xs[0])))
) : [];
};
return append(
lines(node.root.toString()),
drawSubTrees(node.nest)
);
};
// drawTree :: Tree String -> String
const drawTree = tree =>
unlines(draw(tree));
const dctTree = {
"type": "Node",
"root": "alpha",
"nest": [{
"type": "Node",
"root": "beta",
"nest": [{
"type": "Node",
"root": "gamma",
"nest": []
},
{
"type": "Node",
"root": "epsilon",
"nest": []
},
{
"type": "Node",
"root": "eta",
"nest": []
}
]
},
{
"type": "Node",
"root": "iota",
"nest": [{
"type": "Node",
"root": "kappa",
"nest": []
},
{
"type": "Node",
"root": "mu",
"nest": []
},
{
"type": "Node",
"root": "xi",
"nest": []
}
]
},
{
"type": "Node",
"root": "pi",
"nest": [{
"type": "Node",
"root": "rho",
"nest": []
},
{
"type": "Node",
"root": "tau",
"nest": []
},
{
"type": "Node",
"root": "phi",
"nest": []
}
]
},
{
"type": "Node",
"root": "psi",
"nest": []
}
]
};
// GENERIC FUNCTIONS ----------------------------
// append (++) :: [a] -> [a] -> [a] // append (++) :: String -> String -> String const append = (xs, ys) => xs.concat(ys);
// cons :: a -> [a] -> [a]
const cons = (x, xs) =>
Array.isArray(xs) ? (
[x].concat(xs)
) : (x + xs);
// Returns Infinity over objects without finite length // this enables zip and zipWith to choose the shorter // argument when one is non-finite, like cycle, repeat etc
// length :: [a] -> Int const length = xs => xs.length || Infinity;
// lines :: String -> [String] const lines = s => s.split(/[\r\n]/);
// replicate :: Int -> a -> [a]
const replicate = (n, x) =>
Array.from({
length: n
}, () => x);
// shift :: Int -> [a] -> [a]
const shift = (n, xs) => {
const lng = length(xs);
return Infinity > lng ? (
take(lng, drop(n, cycle(xs)))
) : (drop(n, xs), xs);
};
// take :: Int -> [a] -> [a]
// take :: Int -> String -> String
const take = (n, xs) =>
xs.constructor.constructor.name !== 'GeneratorFunction' ? (
xs.slice(0, n)
) : [].concat.apply([], Array.from({
length: n
}, () => {
const x = xs.next();
return x.done ? [] : [x.value];
}));
// unlines :: [String] -> String
const unlines = xs => xs.join('\n');
// Use of `take` and `length` here allows zipping with non-finite lists // i.e. generators like cycle, repeat, iterate.
// zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
const zipWith = (f, xs, ys) => {
const
lng = Math.min(length(xs), length(ys)),
as = take(lng, xs),
bs = take(lng, ys);
return Array.from({
length: lng
}, (_, i) => f(as[i], bs[i], i));
};
// MAIN ---
const strTree = main();
return (
// console.log(strTree),
strTree
);
})();</lang>
- Output:
alpha │ ├─ beta │ │ │ ├─ gamma │ │ │ ├─ epsilon │ │ │ └─ eta │ ├─ iota │ │ │ ├─ kappa │ │ │ ├─ mu │ │ │ └─ xi │ ├─ pi │ │ │ ├─ rho │ │ │ ├─ tau │ │ │ └─ phi │ └─ psi
Julia
Run from Julia REPL. <lang Julia>using Gadfly, LightGraphs, GraphPlot
gx = kronecker(5, 12, 0.57, 0.19, 0.19) gplot(gx) </lang>
Kotlin
<lang scala>// version 1.2.0
import java.util.Random
class Stem(var str: String? = null, var next: Stem? = null)
const val SDOWN = " |" const val SLAST = " `" const val SNONE = " "
val rand = Random()
fun tree(root: Int, head: Stem?) {
val col = Stem()
var head2 = head
var tail = head
while (tail != null) {
print(tail.str)
if (tail.next == null) break
tail = tail.next
}
println("--$root")
if (root <= 1) return
if (tail != null && tail.str == SLAST) tail.str = SNONE
if (tail == null) {
head2 = col
tail = head2
}
else {
tail.next = col
}
var root2 = root
while (root2 != 0) { // make a tree by doing something random
val r = 1 + rand.nextInt(root2)
root2 -= r
col.str = if (root2 != 0) SDOWN else SLAST
tree(r, head2)
}
tail.next = null
}
fun main(args: Array<String>) {
val n = 8 tree(n, null)
}</lang>
Sample output (unlike the C entry, should be different each time it's run):
--8 |--7 | |--6 | | |--5 | | | |--3 | | | | |--2 | | | | | |--1 | | | | | `--1 | | | | `--1 | | | `--2 | | | `--2 | | | |--1 | | | `--1 | | `--1 | `--1 `--1
Lingo
<lang lingo>-- parent script "TreeItem" -- (minimal implementation with direct property access)
property name property children
on new (me, itemName)
me.name = itemName me.children = [] return me
end
on addChild (me, child)
me.children.add(child)
end
-- print a tree on printTree (me, treeItem, indent)
if voidP(treeItem) then treeItem = me if voidP(indent) then indent = "" put indent&treeItem.name repeat with c in treeItem.children me.printTree(c, indent&" ") end repeat
end</lang> Usage: <lang lingo>-- create a tree root = script("TreeItem").new("root") a = script("TreeItem").new("a") root.addChild(a) b = script("TreeItem").new("b") root.addChild(b) a1 = script("TreeItem").new("a1") a.addChild(a1) a11 = script("TreeItem").new("a11") a1.addChild(a11) a12 = script("TreeItem").new("a12") a1.addChild(a12) b1 = script("TreeItem").new("b1") b.addChild(b1)
-- print the tree root.printTree()</lang>
- Output:
-- "root" -- " a" -- " a1" -- " a11" -- " a12" -- " b" -- " b1"
Mathematica
Tree graph
Make a tree graph. In Mathematica, \[DirectedEdge] will appear as an arrow in the code.
<lang Mathematica>edges = {1 \[DirectedEdge] 2, 1 \[DirectedEdge] 3, 2 \[DirectedEdge] 4, 2 \[DirectedEdge] 5,
3 \[DirectedEdge] 6, 4 \[DirectedEdge] 7};
t = TreeGraph[edges, GraphStyle -> "VintageDiagram"]</lang>
Show the syntactical structure of the above code. Defer is added to impede TreeGraph from becoming a graphical object.
<lang Mathematica>TreeForm[Defer@
TreeGraph[{1 \[DirectedEdge] 2, 1 \[DirectedEdge] 3, 2 \[DirectedEdge] 4, 2 \[DirectedEdge] 5,
3 \[DirectedEdge] 6, 4 \[DirectedEdge] 7}, VertexLabels -> "Name"]]</lang>
Opener view
Here's another way to display a tree. The triangles open/close when clicked on.
<lang Mathematica>OpenerView[{1, Column@{OpenerView[{2, Column@{OpenerView[{4, 7}, True], 5}}, True],
OpenerView[{3, OpenerView[{TraditionalForm[Cos[x]], Plot[Cos[x], {x, 0, 10}, ImageSize -> 150]},
True]}, True]}}, True]</lang>
Maxima
<lang maxima>load(graphs)$
g: random_tree(10)$
is_tree(g); true
draw_graph(g)$</lang>
Nim
<lang nim>import strutils
type
Node[T] = ref TNode[T] TNode[T] = object data: T left, right: Node[T]
proc n[T](data: T; left, right: Node[T] = nil): Node[T] =
Node[T](data: data, left: left, right: right)
proc indent[T](n: Node[T]): seq[string] =
if n == nil: return @["-- (null)"]
result = @["--" & $n.data]
for a in indent n.left: result.add " |" & a
let r = indent n.right result.add " `" & r[0] for a in r[1..r.high]: result.add " " & a
let tree = 1.n(2.n(4.n(7.n),5.n),3.n(6.n(8.n,9.n)))
echo tree.indent.join("\n")</lang>
Perl
<lang perl>#!/usr/bin/perl use warnings; use strict; use utf8; use open OUT => ':utf8', ':std';
sub parse {
my ($tree) = shift;
if (my ($root, $children) = $tree =~ /^(.+?)\((.*)\)$/) {
my $depth = 0;
for my $pos (0 .. length($children) - 1) {
my $char = \substr $children, $pos, 1;
if (0 == $depth and ',' eq $$char) {
$$char = "\x0";
} elsif ('(' eq $$char) {
$depth++;
} elsif (')' eq $$char) {
$depth--;
}
}
return($root, [map parse($_), split /\x0/, $children]);
} else { # Leaf.
return $tree;
}
}
sub output {
my ($parsed, $prefix) = @_;
my $is_root = not defined $prefix;
$prefix //= ' ';
while (my $member = shift @$parsed) {
my $last = !@$parsed || (1 == @$parsed and ref $parsed->[0]);
unless ($is_root) {
substr $prefix, -3, 1, ' ';
substr($prefix, -4, 1) =~ s/├/│/;
substr $prefix, -2, 1, ref $member ? ' ' : '└' if $last;
}
if (ref $member) {
output($member, $prefix . '├─');
} else {
print $prefix, $member, "\n";
}
}
}
my $tree = 'a(b0(c1,c2(d(ef,gh)),c3(i1,i2,i3(jj),i4(kk,m))),b1(C1,C2(D1(E),D2,D3),C3))'; my $parsed = [parse($tree)]; output($parsed);</lang>
- Output:
a ├─b0 │ ├─c1 │ ├─c2 │ │ └─d │ │ ├─ef │ │ └─gh │ └─c3 │ ├─i1 │ ├─i2 │ ├─i3 │ │ └─jj │ └─i4 │ ├─kk │ └─m └─b1 ├─C1 ├─C2 │ ├─D1 │ │ └─E │ ├─D2 │ └─D3 └─C3
Perl 6
<lang perl6>sub visualize-tree($tree, &label, &children,
:$indent = ,
:@mid = ('├─', '│ '),
:@end = ('└─', ' '),
) {
sub visit($node, *@pre) {
| gather {
take @pre[0] ~ label($node);
my @children := children($node);
my $end = @children.end;
for @children.kv -> $_, $child {
when $end { take visit($child, (@pre[1] X~ @end)) }
default { take visit($child, (@pre[1] X~ @mid)) }
}
}
}
visit($tree, $indent xx 2);
}
- example tree built up of pairs
my $tree = root=>[a=>[a1=>[a11=>[]]],b=>[b1=>[b11=>[]],b2=>[],b3=>[]]];
.map({.join("\n")}).join("\n").say for visualize-tree($tree, *.key, *.value.list);</lang>
- Output:
root ├─a │ └─a1 │ └─a11 └─b ├─b1 │ └─b11 ├─b2 └─b3
Phix
<lang Phix>function rand_tree(integer low, integer high)
for i=1 to 2 do
integer v = rand(high-low+1)-1+low
if v!=low
and v!=high then
return {v,rand_tree(low,v),rand_tree(v,high)}
end if
end for
return 0
end function
object tree = rand_tree(0,20) -- (can be 0, ~1% chance)
constant Horizontal = #C4,
Horizontals = "\#C4",
TopLeft = #DA,
Vertical = #B3,
BtmLeft = #C0
procedure visualise_tree(object tree, string root=Horizontals)
if atom(tree) then
puts(1,"<empty>\n")
else
object {v,l,r} = tree
integer g = root[$]
if sequence(l) then
root[$] = iff(g=TopLeft or g=Horizontal?' ':Vertical)
visualise_tree(l,root&TopLeft)
end if
root[$] = g
puts(1,root)
?v
if sequence(r) then
root[$] = iff(g=TopLeft?Vertical:' ')
visualise_tree(r,root&BtmLeft)
end if
end if
end procedure
visualise_tree(tree)</lang>
- Output:
┌3 │└4 │ └5 ┌7 ┌9 │└10 │ └11 ─12 │ ┌13 │┌14 └15 │ ┌16 │┌17 ││└18 └19
A much simpler but less aesthetically pleasing way is just <lang Phix>pp(tree,{pp_Nest,10})</lang>
- Output:
{1,
0,
{5,
0,
{9,
{8,
{6,
0,
0},
0},
0}}}
PicoLisp
'view' is a built-in function in PicoLisp.
<lang PicoLisp>(view '(1 (2 (3 (4) (5) (6 (7))) (8 (9)) (10)) (11 (12) (13))))</lang>
Output:
+-- 1
|
+---+-- 2
| |
| +---+-- 3
| | |
| | +---+-- 4
| | |
| | +---+-- 5
| | |
| | +---+-- 6
| | |
| | +---+-- 7
| |
| +---+-- 8
| | |
| | +---+-- 9
| |
| +---+-- 10
|
+---+-- 11
|
+---+-- 12
|
+---+-- 13
Prolog
XPCE
XPCE is the SWI-Prolog native GUI library.
<lang prolog>% direction may be horizontal/vertical/list
display_tree(Direction) :-
sformat(A, 'Display tree ~w', [Direction]),
new(D, window(A)),
send(D, size, size(350,200)),
new(T, tree(text('Root'))),
send(T, neighbour_gap, 10),
new(S1, node(text('Child1'))),
new(S2, node(text('Child2'))),
send_list(T, son,[S1,S2]),
new(S11, node(text('Grandchild1'))),
new(S12, node(text('Grandchild2'))),
send_list(S1, son, [S11, S12]),
new(S21, node(text('Grandchild3'))),
new(S22, node(text('Grandchild4'))),
send_list(S2, son, [S21, S22]),
send(T, direction, Direction),
send(D, display, T),
send(D, open).
</lang>
Python
Library module
Python has the pprint module for pretty-printing data.
If you set the presumed width of the output to 1 then pprint will print each level of a nested tuple (which is Pythons obvious method of creating a tree), on a separate line: <lang python>Python 3.2.3 (default, May 3 2012, 15:54:42) [GCC 4.6.3] on linux2 Type "copyright", "credits" or "license()" for more information. >>> help('pprint.pprint') Help on function pprint in pprint:
pprint.pprint = pprint(object, stream=None, indent=1, width=80, depth=None)
Pretty-print a Python object to a stream [default is sys.stdout].
>>> from pprint import pprint >>> for tree in [ (1, 2, 3, 4, 5, 6, 7, 8), (1, (( 2, 3 ), (4, (5, ((6, 7), 8))))), ((((1, 2), 3), 4), 5, 6, 7, 8) ]: print("\nTree %r can be pprint'd as:" % (tree, )) pprint(tree, indent=1, width=1)
Tree (1, 2, 3, 4, 5, 6, 7, 8) can be pprint'd as: (1,
2, 3, 4, 5, 6, 7, 8)
Tree (1, ((2, 3), (4, (5, ((6, 7), 8))))) can be pprint'd as: (1,
((2,
3),
(4,
(5,
((6,
7),
8)))))
Tree ((((1, 2), 3), 4), 5, 6, 7, 8) can be pprint'd as: ((((1,
2), 3), 4), 5, 6, 7, 8)
>>> </lang>
pprint (and print), prints Pythons standard container types in a format that is valid python so Python could parse its output: <lang python>>>> tree = "a",("b0",("c1","c2",("d",("ef","gh")),"c3",("i1","i2","i3",("jj"),"i4",("kk","m"))),"b1",("C1","C2",("D1",("E"),"D2","D3"),"C3")) >>> pprint(tree, width=1) ('a',
('b0',
('c1',
'c2',
('d',
('ef',
'gh')),
'c3',
('i1',
'i2',
'i3',
'jj',
'i4',
('kk',
'm'))),
'b1',
('C1',
'C2',
('D1',
'E',
'D2',
'D3'),
'C3')))
>>> copypasteoutput = ('a', ... ('b0', ... ('c1', ... 'c2', ... ('d', ... ('ef', ... 'gh')), ... 'c3', ... ('i1', ... 'i2', ... 'i3', ... 'jj', ... 'i4', ... ('kk', ... 'm'))), ... 'b1', ... ('C1', ... 'C2', ... ('D1', ... 'E', ... 'D2', ... 'D3'), ... 'C3'))) >>> tree == copypasteoutput True >>> </lang>
pprints width parameter allows it to fold some structure to better fit the page: <lang python>>>> pprint(tree, width=60) ('a',
('b0',
('c1',
'c2',
('d', ('ef', 'gh')),
'c3',
('i1', 'i2', 'i3', 'jj', 'i4', ('kk', 'm'))),
'b1',
('C1', 'C2', ('D1', 'E', 'D2', 'D3'), 'C3')))
>>> </lang>
pprint works with with a mix of nested container types. Here we create a tree from both lists and tuples: <lang python>>>> mixedtree = ['a', ('b0', ('c1', 'c2', ['d', ('ef', 'gh')], 'c3', ('i1', 'i2', ... 'i3', 'jj', 'i4', ['kk', 'm'])), 'b1', ('C1', 'C2', ('D1', 'E', ... 'D2', 'D3'), 'C3'))] >>> pprint(mixedtree, width=1) ['a',
('b0',
('c1',
'c2',
['d',
('ef',
'gh')],
'c3',
('i1',
'i2',
'i3',
'jj',
'i4',
['kk',
'm'])),
'b1',
('C1',
'C2',
('D1',
'E',
'D2',
'D3'),
'C3'))]
>>> pprint(mixedtree, width=60) ['a',
('b0',
('c1',
'c2',
['d', ('ef', 'gh')],
'c3',
('i1', 'i2', 'i3', 'jj', 'i4', ['kk', 'm'])),
'b1',
('C1', 'C2', ('D1', 'E', 'D2', 'D3'), 'C3'))]
>>> </lang>
Functional composition
Using the same tree structure (including tree node constructor and accessors) as in the Tree Traversal task, and centering parent nodes vertically:
<lang python>Textually visualized tree, with vertically-centered parent nodes
from functools import reduce from itertools import (chain, takewhile)
┌ Epsilon
├─── Zeta
┌─ Beta ┼──── Eta
│ │ ┌───── Mu
│ └── Theta ┤
Alpha ┤ └───── Nu
├ Gamma ────── Xi ─ Omicron
│ ┌─── Iota
└ Delta ┼── Kappa
└─ Lambda
- Tree style and algorithm inspired by Haskell snippet at:
- https://doisinkidney.com/snippets/drawing-trees.html
- drawTree2 :: Bool -> Bool -> Tree a -> String
def drawTree2(blnCompact):
Monospaced UTF8 left-to-right text tree in a
compact or expanded format, with any lines
containing no nodes optionally pruned out.
def go(blnPruned, tree):
# measured :: a -> (Int, String)
def measured(x):
Value of a tree node
tupled with string length
s = ' ' + str(x) + ' '
return (len(s), s)
# lmrFromStrings :: [String] -> ([String], String, [String])
def lmrFromStrings(xs):
(Lefts, mid, Rights)
i = len(xs) // 2
(ls, rs) = (xs[0:i], xs[i:])
return (ls, rs[0], rs[1:])
# stringsFromLMR :: ([String], String, [String])
def stringsFromLMR(lmr):
ls, m, rs = lmr
return ls + [m] + rs
# fghOverLMR
# :: (String -> String)
# -> (String -> String)
# -> (String -> String)
# -> ([String], String, [String])
# -> ([String], String, [String])
def fghOverLMR(f, g, h):
def go(lmr):
ls, m, rs = lmr
return (
[f(x) for x in ls],
g(m),
[h(x) for x in rs]
)
return lambda lmr: go(lmr)
# leftPad :: Int -> String -> String
def leftPad(n):
return lambda s: (' ' * n) + s
# cfix :: Char -> String -> String
def cfix(x):
return lambda xs: x + xs
# treeFix :: (Char, Char, Char) -> ([String], String, [String])
# -> [String]
def treeFix(l, m, r):
return compose(stringsFromLMR)(
fghOverLMR(cfix(l), cfix(m), cfix(r))
)
def lmrBuild(f, w):
def go(wsTree):
nChars, x = wsTree['root']
_x = ('─' * (w - nChars)) + x
xs = wsTree['nest']
lng = len(xs)
# linked :: String -> String
def linked(s):
c = s[0]
t = s[1:]
return _x + '┬' + t if '┌' == c else (
_x + '┤' + t if '│' == c else (
_x + '┼' + t if '├' == c else (
_x + '┴' + t
)
)
)
# LEAF ------------------------------------
if 0 == lng:
return ([], _x, [])
# SINGLE CHILD ----------------------------
elif 1 == lng:
def lineLinked(z):
return _x + '─' + z
rightAligned = leftPad(1 + w)
return fghOverLMR(
rightAligned,
lineLinked,
rightAligned
)(f(xs[0]))
# CHILDREN --------------------------------
else:
rightAligned = leftPad(w)
lmrs = [f(x) for x in xs]
return fghOverLMR(
rightAligned,
linked,
rightAligned
)(
lmrFromStrings(
intercalate([] if blnCompact else ['│'])(
[treeFix(' ', '┌', '│')(lmrs[0])] + [
treeFix('│', '├', '│')(x) for x
in lmrs[1:-1]
] + [treeFix('│', '└', ' ')(lmrs[-1])]
)
)
)
return lambda wsTree: go(wsTree)
measuredTree = fmapTree(measured)(tree)
levelWidths = reduce(
lambda a, xs: a + [max(x[0] for x in xs)],
levels(measuredTree),
[]
)
treeLines = stringsFromLMR(
foldr(lmrBuild)(None)(levelWidths)(
measuredTree
)
)
# lineContainsNode :: String -> Bool
def lineContainsNode(s):
return any(c not in '│ ' for c in s)
return filter(lineContainsNode, treeLines) if (
not blnCompact and blnPruned
) else treeLines
return lambda blnPruned: (
lambda tree: '\n'.join(go(blnPruned, tree))
)
- TEST ----------------------------------------------------
- main :: IO ()
def main():
Trees drawn in varying formats
# tree1 :: Tree Int
tree1 = Node(1)([
Node(2)([
Node(4)([
Node(7)([])
]),
Node(5)([])
]),
Node(3)([
Node(6)([
Node(8)([]),
Node(9)([])
])
])
])
# tree :: Tree String
tree2 = Node('Alpha')([
Node('Beta')([
Node('Epsilon')([]),
Node('Zeta')([]),
Node('Eta')([]),
Node('Theta')([
Node('Mu')([]),
Node('Nu')([])
])
]),
Node('Gamma')([
Node('Xi')([Node('Omicron')([])])
]),
Node('Delta')([
Node('Iota')([]),
Node('Kappa')([]),
Node('Lambda')([])
])
])
print('Fully compacted (parents not centered):')
print((
drawTree2(True)(False)(
tree1
)
))
print('\nExpanded with vertically centered parents:\n')
print((
drawTree2(False)(False)(
tree2
)
))
print('\nCentered parents with nodeless lines pruned out:\n')
print((
drawTree2(False)(True)(
tree2
)
))
- GENERIC -------------------------------------------------
- Node :: a -> [Tree a] -> Tree a
def Node(v):
Contructor for a Tree node which connects a
value of some kind to a list of zero or
more child trees.
return lambda xs: {'type': 'Tree', 'root': v, 'nest': xs}
- compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
def compose(g):
Right to left function composition. return lambda f: lambda x: g(f(x))
- concatMap :: (a -> [b]) -> [a] -> [b]
def concatMap(f):
A concatenated list over which a function has been mapped.
The list monad can be derived by using a function f which
wraps its output in a list,
(using an empty list to represent computational failure).
return lambda xs: list(
chain.from_iterable(map(f, xs))
)
- fmapTree :: (a -> b) -> Tree a -> Tree b
def fmapTree(f):
A new tree holding the results of
applying f to each root in
the existing tree.
def go(x):
return Node(f(x['root']))(
list(map(go, x['nest']))
)
return lambda tree: go(tree)
- foldr :: (a -> b -> b) -> b -> [a] -> b
def foldr(f):
Right to left reduction of a list,
using the binary operator f, and
starting with an initial value a.
return lambda acc: lambda xs: reduce(
f, xs[::-1], acc
)
- intercalate :: [a] -> a -> [a]
- intercalate :: String -> [String] -> String
def intercalate(x):
The concatenation of xs
interspersed with copies of x.
return lambda xs: x.join(xs) if isinstance(x, str) else list(
chain.from_iterable(
reduce(lambda a, v: a + [x, v], xs[1:], [xs[0]])
)
) if xs else []
- iterate :: (a -> a) -> a -> Gen [a]
def iterate(f):
An infinite list of repeated
applications of f to x.
def go(x):
v = x
while True:
yield v
v = f(v)
return lambda x: go(x)
- levels :: Tree a -> a
def levels(tree):
A list of the nodes at each level of the tree.
return list(
map_(map_(root))(
takewhile(
bool,
iterate(concatMap(nest))(
[tree]
)
)
)
)
- map :: (a -> b) -> [a] -> [b]
def map_(f):
The list obtained by applying f
to each element of xs.
return lambda xs: list(map(f, xs))
- nest :: Tree a -> [Tree a]
def nest(t):
Accessor function for children of tree node. return t['nest'] if 'nest' in t else None
- root :: Tree a -> a
def root(t):
Accessor function for data of tree node. return t['root'] if 'root' in t else None
- MAIN ---
if __name__ == '__main__':
main()</lang>
- Output:
Fully compacted (parents not centered):
┌ 4 ─ 7
┌ 2 ┴ 5
1 ┤ ┌ 8
└ 3 ─ 6 ┴ 9
Expanded with vertically centered parents:
┌ Epsilon
│
├─── Zeta
│
┌─ Beta ┼──── Eta
│ │
│ │ ┌───── Mu
│ └── Theta ┤
Alpha ┤ └───── Nu
│
├ Gamma ────── Xi ─ Omicron
│
│ ┌─── Iota
│ │
└ Delta ┼── Kappa
│
└─ Lambda
Centered parents with nodeless lines pruned out:
┌ Epsilon
├─── Zeta
┌─ Beta ┼──── Eta
│ │ ┌───── Mu
│ └── Theta ┤
Alpha ┤ └───── Nu
├ Gamma ────── Xi ─ Omicron
│ ┌─── Iota
└ Delta ┼── Kappa
└─ Lambda
Or using the same data structures, but generating a simpler (decorated outline) visualisation:
<lang python>Visualize a tree
from itertools import (repeat, starmap) from operator import (add)
- drawTree :: Tree a -> String
def drawTree(tree):
ASCII diagram of a tree. return '\n'.join(draw(tree))
- draw :: Tree a -> [String]
def draw(node):
List of the lines of an ASCII
diagram of a tree.
def shift(first, other, xs):
return list(starmap(
add,
zip(
[first] + list(
repeat(other, len(xs) - 1)
),
xs
)
))
def drawSubTrees(xs):
return (
(
['│'] + shift(
'├─ ', '│ ', draw(xs[0])
) + drawSubTrees(xs[1:])
) if 1 < len(xs) else ['│'] + shift(
'└─ ', ' ', draw(xs[0])
)
) if xs else []
return (str(root(node))).splitlines() + (
drawSubTrees(nest(node))
)
- TEST ----------------------------------------------------
- main :: IO ()
def main():
Test
# tree :: Tree Int
tree = Node(1)([
Node(2)([
Node(4)([
Node(7)([])
]),
Node(5)([])
]),
Node(3)([
Node(6)([
Node(8)([]),
Node(9)([])
])
])
])
print(drawTree(tree))
- GENERIC -------------------------------------------------
- Node :: a -> [Tree a] -> Tree a
def Node(v):
Contructor for a Tree node which connects a
value of some kind to a list of zero or
more child trees.
return lambda xs: {'type': 'Node', 'root': v, 'nest': xs}
- nest :: Tree a -> [Tree a]
def nest(tree):
Accessor function for children of tree node. return tree['nest'] if 'nest' in tree else None
- root :: Dict -> a
def root(dct):
Accessor function for data of tree node. return dct['root'] if 'root' in dct else None
- MAIN ---
if __name__ == '__main__':
main()</lang>
- Output:
1
│
├─ 2
│ │
│ ├─ 4
│ │ │
│ │ └─ 7
│ │
│ └─ 5
│
└─ 3
│
└─ 6
│
├─ 8
│
└─ 9
Racket
<lang Racket>
- lang racket/base
(define (visualize t0)
(let loop ([t t0] [last? #t] [indent '()])
(define (I mid last) (cond [(eq? t t0) ""] [last? mid] [else last]))
(for-each display (reverse indent))
(unless (eq? t t0) (printf "|\n"))
(for-each display (reverse indent))
(printf "~a~a\n" (I "\\-" "+-") (car t))
(for ([s (cdr t)] [n (in-range (- (length t) 2) -1 -1)])
(loop s (zero? n) (cons (I " " "| ") indent)))))
(visualize '(1 (2 (3 (4) (5) (6 (7))) (8 (9)) (10)) (11 (12) (13)))) </lang>
Output:
1 | +-2 | | | +-3 | | | | | +-4 | | | | | +-5 | | | | | \-6 | | | | | \-7 | | | +-8 | | | | | \-9 | | | \-10 | \-11 | +-12 | \-13
REXX
<lang rexx>/* REXX ***************************************************************
- 10.05.2014 Walter Pachl using the tree and the output format of C
- /
Call mktree Say node.1.0name Call tt 1, Exit
tt: Procedure Expose node. /**********************************************************************
- show a subtree (recursively)
- /
Parse Arg k,st
Do i=1 To node.k.0
If i=node.k.0 Then
s='`--'
Else
s='|--'
c=node.k.i
If st<> Then
st=left(st,length(st)-2)' '
st=changestr('` ',st,' ')
Say st||s||node.c.0name
Call tt c,st||s
End
Return
Exit
mktree: Procedure Expose node. root /**********************************************************************
- build the tree according to the task
- /
node.=0
r=mknode('R');
a=mknode('A'); Call attchild a,r
b=mknode('B'); Call attchild b,a
c=mknode('C'); Call attchild c,a
d=mknode('D'); Call attchild d,b
e=mknode('E'); Call attchild e,b
f=mknode('F'); Call attchild f,b
g=mknode('G'); Call attchild g,b
h=mknode('H'); Call attchild h,d
i=mknode('I'); Call attchild i,h
j=mknode('J'); Call attchild j,i
k=mknode('K'); Call attchild k,j
l=mknode('L'); Call attchild l,j
m=mknode('M'); Call attchild m,e
n=mknode('N'); Call attchild n,e
Return
mknode: Procedure Expose node. /**********************************************************************
- create a new node
- /
Parse Arg name z=node.0+1 node.z.0name=name node.0=z Return z /* number of the node just created */
attchild: Procedure Expose node. /**********************************************************************
- make a the next child of father
- /
Parse Arg a,father node.a.0father=father z=node.father.0+1 node.father.z=a node.father.0=z node.a.0level=node.father.0level+1 Return
</lang>
- Output:
R `--A |--B | |--D | | `--H | | `--I | | `--J | | |--K | | `--L | |--E | | |--M | | `--N | |--F | `--G `--C
Ruby
Modifying Tree_traversal#Ruby by adding somewhere after the line <lang Ruby> root = BinaryTreeNode.from_array [1, [2, [4, 7], [5]], [3, [6, [8], [9]]]] </lang> the lines <lang Ruby> require 'pp' pp root </lang> will produce:
- Output:
#<BinaryTreeNode:0x804f854
@left=
#<BinaryTreeNode:0x804fad8
@left=#<BinaryTreeNode:0x804fc28 @left=nil, @right=nil, @value=7>,
@right=nil,
@value=4>,
@right=#<BinaryTreeNode:0x804f9c0 @left=nil, @right=nil, @value=5>,
@value=2>,
@right=
#<BinaryTreeNode:0x804f074
@left=
#<BinaryTreeNode:0x804f218
@left=#<BinaryTreeNode:0x804f544 @left=nil, @right=nil, @value=8>,
@right=#<BinaryTreeNode:0x804f384 @left=nil, @right=nil, @value=9>,
@value=6>,
@right=nil,
@value=3>,
@value=1>
<lang Ruby> def ptree(tree,indent=" ")
case tree
when Array
head,*tail=tree
ptree(head,indent)
s=tail.size-1
tail.each_with_index { |tree1,i| ptree(tree1,"#{indent}#{((i==s) ? ' ':'|')} ") }
else
puts(indent.gsub(/\s\s$/,"--").gsub(/ --$/,"\\--")+tree.to_s)
end
end ptree [1,2,3,[4,5,6,[7,8,9]],3,[22,33]] </lang> will produce:
- Output:
--1
|--2
|--3
|--4
| |--5
| |--6
| \--7
| |--8
| \--9
|--3
\--22
\--33
Rust
Console visualization of binary trees translated from parts of the C AVL tree solution. <lang Rust> extern crate rustc_serialize; extern crate term_painter;
use rustc_serialize::json; use std::fmt::{Debug, Display, Formatter, Result}; use term_painter::ToStyle; use term_painter::Color::*;
type NodePtr = Option<usize>;
- [derive(Debug, PartialEq, Clone, Copy)]
enum Side {
Left, Right, Up,
}
- [derive(Debug, PartialEq, Clone, Copy)]
enum DisplayElement {
TrunkSpace, SpaceLeft, SpaceRight, SpaceSpace, Root,
}
impl DisplayElement {
fn string(&self) -> String {
match *self {
DisplayElement::TrunkSpace => " │ ".to_string(),
DisplayElement::SpaceRight => " ┌───".to_string(),
DisplayElement::SpaceLeft => " └───".to_string(),
DisplayElement::SpaceSpace => " ".to_string(),
DisplayElement::Root => "├──".to_string(),
}
}
}
- [derive(Debug, Clone, Copy, RustcDecodable, RustcEncodable)]
struct Node<K, V> {
key: K, value: V, left: NodePtr, right: NodePtr, up: NodePtr,
}
impl<K: Ord + Copy, V: Copy> Node<K, V> {
pub fn get_ptr(&self, side: Side) -> NodePtr {
match side {
Side::Up => self.up,
Side::Left => self.left,
_ => self.right,
}
}
}
- [derive(Debug, RustcDecodable, RustcEncodable)]
struct Tree<K, V> {
root: NodePtr, store: Vec<Node<K, V>>,
}
impl<K: Ord + Copy + Debug + Display, V: Debug + Copy + Display> Tree<K, V> {
pub fn get_node(&self, np: NodePtr) -> Node<K, V> {
assert!(np.is_some());
self.store[np.unwrap()]
}
pub fn get_pointer(&self, np: NodePtr, side: Side) -> NodePtr {
assert!(np.is_some());
self.store[np.unwrap()].get_ptr(side)
}
// Prints the tree with root p. The idea is to do an in-order traversal
// (reverse in-order in this case, where right is on top), and print nodes as they
// are visited, one per line. Each invocation of display() gets its own copy
// of the display element vector e, which is grown with either whitespace or
// a trunk element, then modified in its last and possibly second-to-last
// characters in context.
fn display(&self, p: NodePtr, side: Side, e: &Vec<DisplayElement>, f: &mut Formatter) {
if p.is_none() {
return;
}
let mut elems = e.clone();
let node = self.get_node(p);
let mut tail = DisplayElement::SpaceSpace;
if node.up != self.root {
// If the direction is switching, I need the trunk element to appear in the lines
// printed before that node is visited.
if side == Side::Left && node.right.is_some() {
elems.push(DisplayElement::TrunkSpace);
} else {
elems.push(DisplayElement::SpaceSpace);
}
}
let hindex = elems.len() - 1;
self.display(node.right, Side::Right, &elems, f);
if p == self.root {
elems[hindex] = DisplayElement::Root;
tail = DisplayElement::TrunkSpace;
} else if side == Side::Right {
// Right subtree finished
elems[hindex] = DisplayElement::SpaceRight;
// Prepare trunk element in case there is a left subtree
tail = DisplayElement::TrunkSpace;
} else if side == Side::Left {
elems[hindex] = DisplayElement::SpaceLeft;
let parent = self.get_node(node.up);
if parent.up.is_some() && self.get_pointer(parent.up, Side::Right) == node.up {
// Direction switched, need trunk element starting with this node/line
elems[hindex - 1] = DisplayElement::TrunkSpace;
}
}
// Visit node => print accumulated elements. Each node gets a line and each line gets a
// node.
for e in elems.clone() {
let _ = write!(f, "{}", e.string());
}
let _ = write!(f,
"{key:>width$} ",
key = Green.bold().paint(node.key),
width = 2);
let _ = write!(f,
"{value:>width$}\n",
value = Blue.bold().paint(format!("{:.*}", 2, node.value)),
width = 4);
// Overwrite last element before continuing traversal
elems[hindex] = tail;
self.display(node.left, Side::Left, &elems, f); }
}
impl<K: Ord + Copy + Debug + Display, V: Debug + Copy + Display> Display for Tree<K, V> {
fn fmt(&self, f: &mut Formatter) -> Result {
if self.root.is_none() {
write!(f, "[empty]")
} else {
let mut v: Vec<DisplayElement> = Vec::new();
self.display(self.root, Side::Up, &mut v, f);
Ok(())
}
}
}
/// Decodes and prints a previously generated tree. fn main() {
let encoded = r#"{"root":0,"store":[{"key":0,"value":0.45,"left":1,"right":3,
"up":null},{"key":-8,"value":-0.94,"left":7,"right":2,"up":0}, {"key":-1,
"value":0.15,"left":8,"right":null,"up":1},{"key":7, "value":-0.29,"left":4,
"right":9,"up":0},{"key":5,"value":0.80,"left":5,"right":null,"up":3},
{"key":4,"value":-0.85,"left":6,"right":null,"up":4},{"key":3,"value":-0.46,
"left":null,"right":null,"up":5},{"key":-10,"value":-0.85,"left":null,
"right":13,"up":1},{"key":-6,"value":-0.42,"left":null,"right":10,"up":2},
{"key":9,"value":0.63,"left":12,"right":null,"up":3},{"key":-3,"value":-0.83,
"left":null,"right":11,"up":8},{"key":-2,"value":0.75,"left":null,"right":null,
"up":10},{"key":8,"value":-0.48,"left":null,"right":null,"up":9},{"key":-9,
"value":0.53,"left":null,"right":null,"up":7}]}"#;
let tree: Tree<i32, f32> = json::decode(&encoded).unwrap();
println!("{}", tree);
} </lang>
- Output:
Sidef
<lang ruby>func visualize_tree(tree, label, children,
indent = ,
mids = ['├─', '│ '],
ends = ['└─', ' '],
) {
func visit(node, pre) {
gather {
take(pre[0] + label(node))
var chldn = children(node)
var end = chldn.end
chldn.each_kv { |i, child|
if (i == end) { take(visit(child, [pre[1]] ~X+ ends)) }
else { take(visit(child, [pre[1]] ~X+ mids)) }
}
}
}
visit(tree, [indent] * 2)
}
var tree = 'root':['a':['a1':['a11':[]]],'b':['b1':['b11':[]],'b2':[],'b3':[]]] say visualize_tree(tree, { .first }, { .second }).flatten.join("\n")</lang>
- Output:
root ├─a │ └─a1 │ └─a11 └─b ├─b1 │ └─b11 ├─b2 └─b3
Tcl
<lang tcl>package require struct::tree
proc visualize_tree {tree {nameattr name}} {
set path {}
$tree walk [$tree rootname] -order both {mode node} {
if {$mode eq "enter"} { set s "" foreach p $path { append s [expr {[$tree next $p] eq "" ? " " : "\u2502 "}] } lappend path $node append s [expr { [$tree next $node] eq "" ? "\u2514\u2500" : "\u251c\u2500" }] if {[$tree keyexists $node $nameattr]} { set name [$tree get $node $nameattr] } else { # No node name attribute; use the raw name set name $node } puts "$s$name" } else { set path [lrange $path 0 end-1] }
}
}</lang> Demonstrating: <lang tcl># Sample tree to demonstrate with struct::tree t deserialize {root {} {} a 0 {} d 3 {} e 3 {} f 9 {} b 0 {} c 0 {}} visualize_tree t</lang>
- Output:
└─root ├─a │ ├─d │ └─e │ └─f ├─b └─c
Yabasic
<lang Yabasic>clear screen
dim colore$(1)
maxCol = token("white yellow cyan green red", colore$())
showTree(0, "[1[2[3][4[5][6]][7]][8[9]]]") print "\n\n\n" showTree(0, "[1[2[3[4]]][5[6][7[8][9]]]]")
sub showTree(n, A$)
local i, c$
static co
c$ = left$(A$, 1)
if c$ = "" return
switch c$
case "[": co = co + 1 : showTree(n + 1, right$(A$, len(A$) - 1))
break
case "]": co = co - 1 : showTree(n - 1, right$(A$, len(A$) - 1))
break
default: for i = 2 to n
print " ";
next i
co = max(min(co, maxCol), 1)
print color(colore$(co)) "\xc0-", c$
showTree(n, right$(A$, len(A$) - 1))
break
end switch
end sub </lang>
zkl
In zkl, the Vault is a global object store object (aka thread safe dictionary). Basically a tiny file system for objects. It has a "dir" method to display the contents
- Output:
:Vault.dir()
...
Compiler
Asm
Compiler
Dictionary
Exception
Test
UnitTester
foo
bar
...
It does this with data that looks like: L("Network.TCPServerSocket","File","ZKLShell.Granny","Int","startup","Utils.Inspector","Thread.Straw","Ref","Utils.Argh" ...) <lang zkl>fcn vaultDir(out=Console){
const INDENT=" ";
space:=""; lastPath:=L();
foreach fullname in (TheVault.BaseClass.contents.sort()){
path:=fullname.split("."); name:=path.pop();
if(lastPath==path) out.writeln(space,name);
else{
n:=0; p:=path.copy(); try{ while(path[0]==lastPath[0]) { n+=1; path.pop(0); lastPath.pop(0); } }catch{} space=INDENT*n; foreach dir in (path){ out.writeln(space,dir); space+=INDENT; } out.writeln(space,name); lastPath=p;
} } "" // so startup has something to display
} </lang>
- Programming Tasks
- Solutions by Programming Task
- 11l
- Ada
- ALGOL 68
- Batch File
- BBC BASIC
- C
- Clojure
- Common Lisp
- D
- Elena
- Erlang
- F Sharp
- Factor
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