Towers of Hanoi

globals 
[
  SETA 
  SETB 
  SETC 
  DISKA
  DISKB
  DISKC
  delsize
]

to setup 
  reset-ticks
  set SETA [0 0 0 0 0 0 0 0 0 0]
  set SETB [0 0 0 0 0 0 0 0 0 0]
  set SETC [0 0 0 0 0 0 0 0 0 0]
  set DISKA Numdisks
  set DISKB 0
  set DISKC 0
  installdisk Numdisks -19 5 
end 

to go
  ToH 1 2 3 Numdisks
  print (word "Total steps taken" ticks)
end 

to installdisk [numbe xcord ycord]
  if(numbe > 0)[
  makedisk numbe xcord ycord
  set SETA replace-item (DISKA - numbe) SETA numbe
  set ycord ycord - 1
  set numbe numbe - 1
  installdisk numbe xcord ycord 
  ]
end   

to makedisk [numb xcord ycord]
  if(numb > 0)[
      ask patch (xcord + numb) (- ycord) [set pcolor blue]
      set numb numb - 1
      makedisk numb xcord ycord
  ]
end 

to deldisk[numb xcord ycord]
  if(numb > 0)[
      ask patch (xcord + numb) (- ycord) [set pcolor black]
      set numb numb - 1
      deldisk numb xcord ycord
  ]
end 

to alterdisk [a c]
   if(a = 1)[
     set delsize (item (DISKA - 1) SETA )
     deldisk delsize -19 (5 - DISKA + 1) 
     set DISKA DISKA - 1
     set SETA replace-item (DISKA) SETA 0
   ]
   
   if(a = 2)[
     set delsize (item (DISKB - 1) SETB )
     deldisk delsize -7 (5 - DISKB + 1) 
     set DISKB DISKB - 1
     set SETB replace-item (DISKB) SETB 0
   ]
   
   if(a = 3)[
     set delsize (item (DISKC - 1) SETC )
     deldisk delsize 5 (5 - DISKC + 1) 
     set DISKC DISKC - 1
     set SETC replace-item (DISKC) SETC 0
   ]
   
   if(c = 3)[
     let addsize delsize
     makedisk addsize 5 (5 - DISKC)
     set SETC replace-item (DISKC) SETC addsize
     set DISKC DISKC + 1
   ]
   
   if(c = 2)[
     let addsize delsize
     makedisk addsize -7 (5 - DISKB)
     set SETB replace-item (DISKB) SETB addsize
     set DISKB DISKB + 1
   ]
   
   if(c = 1)[
     let addsize delsize
     makedisk addsize -19 (5 - DISKA)
     set SETA replace-item (DISKA) SETA addsize
     set DISKA DISKA + 1
   ]
end 

to ToH [a b c n]
  let num 0
   ifelse(n = 1)[
     alterdisk a c
     tick
     show SETA
     show SETB
     show SETC
   ]
   [
     set num n - 1
     ToH a c b num
     alterdisk a c
     tick
     ToH b a c num
      show SETA
     show SETB
     show SETC
   ]
end