At Friday 11/8/2006 18:04, Dr. Pastor wrote:
Attempting to learn Python; I constructed the module
listed below. I would like to make it shorter, faster,
more "Python like". (Windows XP, Pro.)
Many thanks for any advice!
...
#-------------------------------------------------------------------------------
# Name: SendMoreMoney.py
# Purpose: A solution to the SEND+MORE=MONEY puzzle.
#
# Author: Dr. Pastor
#
# Copyright: (c) Dr. Pastor 2006
#-------------------------------------------------------------------------------
#!/usr/bin/env python
This line is not used on Windows, but if you want to include it, must
be the very first line on the script.
#
# The solution for the puzzle of
# SEND
# +MORE
# -----
# MONEY
#
def perm(items, n=None):
if n is None:
n = len(items)
for i in range(len(items)):
v = items[i:i+1]
I would use v = [items[i]] but that's a matter of taste...
if n == 1:
yield v
else:
rest = items[:i] + items[i+1:]
for p in perm(rest, n-1):
yield v + p
def comb(items, n=None):
if n is None:
n = len(items)
for i in range(len(items)):
v = items[i:i+1]
Same as above.
if n == 1:
yield v
else:
rest = items[i+1:]
for c in comb(rest, n-1):
yield v + c
#
# S E N D M O R Y
# ['0','1','2','3','4','5','6','7','8','9']
#
print
print "Selections of 8 items from 10 then the permutation of them."
print
b=0
for s in comb([0,1,2,3,4,5,6,7,8,9],8):
for a in perm(s,None):
if (a[4]*1000+a[5]*100+a[2]*10+a[1])*10+a[7] == \
(a[0]+a[4])*1000+(a[1]+a[5])*100+(a[2]+a[6])*10+(a[3]+a[1]):
Backslash as continuation is a bit problematic (add an empty space
after it and it's broken...) so it's better to add an open parens;
continuation is implicit until the last parens is closed:
if (a[4]*10000+a[5]*1000+a[2]*100+a[1]*10+a[7] ==
(a[0]+a[4])*1000+(a[1]+a[5])*100+(a[2]+a[6])*10+(a[3]+a[1])):
If speed is not the most important thing, you could assign names to
the 8 items:
S, E, N, D, M, O, R, Y = a
if poly(10, M,O,N,E,Y) == poly(10, S,E,N,D) + poly(10, M,O,R,E):
which is infinitely more legible (and a bit compact, too).
(poly is left as an exercise: def poly(x, *args): )
And a,b,s are too short names...
Gabriel Genellina
Softlab SRL
__________________________________________________
Preguntá. Respondé. Descubrí.
Todo lo que querías saber, y lo que ni imaginabas,
está en Yahoo! Respuestas (Beta).
¡Probalo ya!
http://www.yahoo.com.ar/respuestas
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