unit Treeunit;

interface

Procedure Init_Tree(Root:ttree);
procedure Insert(var Root: TTree; X: T);
procedure Delete(Root: TTree);
procedure LeafsCount(Root: TTree; var k: Integer);
procedure Printtree(T:TTree;h:integer);
function Leaves(t: ttree): integer;

implementation

Procedure Init_Tree(Root:ttree);
 begin
  root:=nil
 end;

procedure Insert(var Root: TTree; X: T);

	procedure CreateNode(var p: TTree; n: T);
	begin
		New(p);
		p^.value := n;
		p^.Left := nil;
		p^.Right := nil
	end;
	
begin
	if Root = nil then CreateNode(Root, X)
	else
		with Root^ do begin
			if value < X then Insert(Right, X)
			else
				if value > X then Insert(Left, X)
		end;
end;
procedure Delete(Root: TTree);
begin
	if Root = nil then exit;

	Delete(Root^.Right);
	Delete(Root^.Left);
	Dispose(Root)
end;
procedure Printtree(T:TTree;h:integer);
var i:integer;
begin
	if T<>nil then
	   with T^ do
      begin
       Printtree(right,h+3);
        for i:=1 to h do
         write(' ');
         write(info);
         writeln;
		     Printtree(left,h+3)
      end
end;
procedure LeafsCount(Root: TTree; var k: Integer);
begin
	if Root <> nil then begin
		LeafsCount(Root^.Left, k);
		if (Root^.Left = nil) and (Root^.Right = nil) then Inc(k);
		LeafsCount(Root^.Right, k)
	end
end;

function Leaves(t: ttree): integer;
const
max_nodes = 100;
var
  st: array[1 .. max_nodes] of ttree;
  sp, counter: integer;
begin
  sp := 0; counter := 0;
  repeat
    while t <> nil do
    begin
      inc(sp);
      st[sp] := t;
      t := t^.left;
    end;
    if sp = 0 then
    begin
      Leaves := counter;
      exit;
    end;
    t := st[sp];
    dec(sp);
  if (T^.right = nil) and (T^.left = nil) then
    inc(counter);
    t := t^.right;
   until false;
end;
end.