Data commit

Task/Visualize-a-tree/Delphi/visualize-a-tree.delphi

@@ -0,0 +1,80 @@
+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.