#!/usr/bin/python
###########################################################################
#
#   Konjicek - graf skokov sahovskega konjicka
#
#   import sys; wdir = r'D:\2008\Python\DMFA\konjicek'; sys.path.append(wdir)
#
#   import konjicek;  konjicek.run(wdir,4,4)
#   reload(konjicek); konjicek.run(wdir,4,4)
#
#   Vladimir Batagelj,  16. januar 2008
#
###########################################################################

import string, os, sys, datetime

def ind(i,j):
   global n, m
   return 1 + i*m + j

def naPlosci(p,q):
   global n, m
   return (0<=p) and (p<n) and (0<=q) and (q<m)

def run(wdir,n0=8,m0=8):
   global n, m
   m = m0; n=n0
   ime = 'konjicek'+str(n)+'x'+str(m)
   print "\n*** Konjicek\nV. Batagelj, Januar 16, 2008 / Januar 16, 2008\n"
   print "konjicek ",n,"x",m
   net  = open(wdir+'\\'+ime+'.net', 'w')
   net.write('% '+ime+' - ' + datetime.datetime.now().ctime()+"\n")
   net.write('*vertices '+str(n*m)+'\n')
   for i in range(n):
      for j in range(m):
         net.write(str(ind(i,j))+' "('+str(i+1)+':'+str(j+1)+')"\n')
   net.write('*edges\n')
   pomik = [(-1,-2),(1,-2),(2,-1),(2,1),(1,2),(-1,2),(-2,1),(-2,-1)]
   for i in range(n):
      for j in range(m):
         for u,v in pomik:
            (p,q) = (i+v,j+u)
            if naPlosci(p,q) and p<i:
               net.write(str(ind(i,j))+' '+str(ind(p,q))+'\n')
   net.close()
   print "\nkonec\n"
# --------------------------