Visualize a tree: Difference between revisions

=={{header|Delphi}}==

{{libheader| System.SysUtils}}

{{Trans|Go}}

<lang Delphi>

program Visualize_a_tree;

{$APPTYPE CONSOLE}

uses

System.SysUtils;

type

TNode = record

_label: string;

children: TArray<Integer>;

end;

TTree = TArray<TNode>;

TTreeHelper = record helper for TTree

procedure AddNode(lb: string; chl: TArray<Integer> = []);

end;

procedure Vis(t: TTree);

procedure f(n: Integer; pre: string);

begin

var ch := t[n].children;

if Length(ch) = 0 then

begin

Writeln('-', t[n]._label);

exit;

end;

writeln('+', t[n]._label);

var last := Length(ch) - 1;

for var c in copy(ch, 0, last) do

begin

write(pre, '+-');

f(c, pre + '¦ ');

end;

write(pre, '+-');

f(ch[last], pre + ' ');

end;

begin

if Length(t) = 0 then

begin

writeln('<empty>');

exit;

end;

f(0, '');

end;

{ TTreeHelper }

procedure TTreeHelper.AddNode(lb: string; chl: TArray<Integer> = []);

begin

SetLength(self, Length(self) + 1);

with self[High(self)] do

begin

_label := lb;

if Length(chl) > 0 then

children := copy(chl, 0, length(chl));

end;

end;

var

Tree: TTree;

begin

Tree.AddNode('root', [1, 2, 3]);

Tree.AddNode('ei', [4, 5]);

Tree.AddNode('bee');

Tree.AddNode('si');

Tree.AddNode('dee');

Tree.AddNode('y', [6]);

Tree.AddNode('eff');

Vis(Tree);

{$IFNDEF UNIX} readln; {$ENDIF}

end.</lang>

{{out}}

<pre>┐root

├─┐ei

│ ├──dee

│ └─┐y

│ └──eff

├──bee

└──si</pre>