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# This is just a small python snippet to lexicographic print permutation from 0 to 9 .. like # 0 1 2 3 4 5 6 7 8 9 # 0 1 2 3 4 5 6 7 9 8 # 0 1 2 3 4 5 6 8 7 9 # 0 1 2 3 4 5 6 8 9 7 # 0 1 2 3 4 5 6 9 7 8 # 0 1 2 3 4 5 6 9 8 7 # 0 1 2 3 4 5 7 6 8 9 # I am just a newbie learning programming with python, so excuse my bad coding ;)

import sys count = 0 for a in range(0,10): table = [False,False,False,False,False,False,False,False,False,False] table[a] = True for b in range(0,10): if not table[b]: table[b] = True for c in range(0,10): if not table[c]: table[c] = True for d in range(0,10): if not table[d]: table[d] = True for e in range(0,10): if not table[e]: table[e] = True for f in range(0,10): if not table[f]: table[f] = True for g in range(0,10): if not table[g]: table[g] = True for h in range(0,10): if not table[h]: table[h] = True for i in range(0,10): if not table[i]: table[i] = True for j in range(0,10): if not table[j]: print a,b,c,d,e,f,g,h,i,j count = count + 1 table[j] = False table[i] = False table[h] = False table[g] = False table[f] = False table[e] = False table[d] = False table[c] = False table[b] = False

## Comments

## bela dona replied on Mon, 2009/05/18 - 7:41am

## flash tring replied on Thu, 2009/04/23 - 6:07am

## fien terst replied on Wed, 2009/04/22 - 1:22am

## Snippets Manager replied on Tue, 2009/04/21 - 1:41pm

## sdadfam faomdm replied on Sat, 2009/04/18 - 10:38am

## Snippets Manager replied on Fri, 2009/02/20 - 3:04pm

## Snippets Manager replied on Wed, 2009/01/07 - 1:02am

`#dummy functions which are good examples of callbacks! def printer(x): print(x) return True def returner(x): return(x) # this one can do want you want and is very readable, but still recursive! def permute_readable_version(table=range(10), permutation=[], num_items=10, callback=printer): if len(permutation) == num_items or len(table)==0: return [callback(permutation)] permutations=[] for i in range(len(table)): permutations+=permute_readable(table[:i]+table[i+1:], permutation+[table[i]], num_items, callback) return permutations # this one can do the same thing and is hard to read but even faster! def permute(table=range(10), permutation=[], num_items=10, callback=printer): if len(permutation) == num_items or len(table)==0: return [callback(permutation)] return sum([permute(table[:i]+table[i+1:], permutation+[table[i]], num_items, callback) for i in range(len(table))],[]) # Try uncommenting the below line! #results=permute() # I set all the default values so it'll do exactly what you want! # If you use a dummy return function for every permutation, # you get back a list of all the permutations. # Without using messy messy global variables! # But careful! Huge lists of thousands of permutations can crash you # if they're all in memory at once! That's what callbacks are for! couples_permutation= permute(['joe six-pack', 'jesus', 'margaret thatcher', 'sarah palin', 'george bush', 'vishnu'], num_items=2, callback=returner) couples_combinatorial=[] for couple in couples_permutation: if sorted(couple) not in couples_combinatorial: couples_combinatorial.append(sorted(couple)) print("\n Who do you think would make a good couple?\n") for couple in couples_combinatorial: print(' %s with %s?' % (couple[0],couple[1])) print("\n There are %s possible couples listed.\n" % len(couples_combinatorial))`