verbatimtex
\documentclass[12pt]{article}
\usepackage[T1]{fontenc}
\usepackage{euler}
\usepackage{times}
\begin{document}
etex;

defaultfont := "cmr12";
defaultscale := 12pt /fontsize defaultfont;
input mp-tool;
prologues := 2;
input marctree;

beginfig( 0 );
  picture t[];
  numeric len;
  len = 5cm;

  leaf.t0( btex 0 etex );
  leaf.t1( btex 1 etex );
  for i = 2 upto 15:
    node.t[i];
    branches.t[i]( t[ i div 2 ], t[ i mod 2 ] );
    t[i].distx := 0.5cm;
    t[i].disty := 0.5cm;
  endfor;
  for i = 0 upto 15:
    drawarrow 4mm*up rotated (i * 360 / 16)--(len-1cm)*up rotated (i * 360 / 16)
              withpen pencircle scaled 1pt
              withcolor red;
    label( decimal( i ), (len-5mm)*up rotated (i * 360 / 16) );
    draw treeit( t[ i ] )
         rotated (i * 360 / 16)
         shifted (len*up rotated (i * 360 / 16))
         withcolor blue;
  endfor;
  setbounds currentpicture to boundingbox currentpicture enlarged 2pt; 
endfig;

beginfig( 1 );
  picture d, h, e, l, o, r, w, hello, space, bang;

  leaf.d( btex d etex );
  leaf.h( btex H etex );
  leaf.e( btex e etex );
  leaf.l( btex l etex );
  leaf.o( btex o etex );
  leaf.r( btex r etex );
  leaf.w( btex w etex );
  leaf.bang( btex ! etex );
  node.space;
  node.hello;
  branches.hello( h, e, l, l, o, space, w, o, r, l, d, bang );
  hello.distx := 1.2mm;

  draw treeit( hello );
  setbounds currentpicture to boundingbox currentpicture enlarged 2pt; 
endfig;

beginfig( 2 );
  picture b, c, d, e, f;

  leaf.a( btex a etex );
  leaf.b( btex b etex );
  leaf.c( btex c etex );
  leaf.d( btex d etex );
  leaf.f( btex f etex );
  leaf.g( btex g etex );
  branches.f( g );
  branches.e( f, g );
  branches.d( e, f, g );
  branches.c( d, e, f, g );
  branches.b( c, d, e, f, g );
  b.distx :=  5mm;
  b.disty := 15mm;
  draw treeit( b );
  setbounds currentpicture to boundingbox currentpicture enlarged 2pt; 
endfig;

end