Using Psyco this version is much faster, you can test it on your PC
compared to the other one (the whole running time, Psyco compilation
too):
Psyco is unable to speed up generator functions, so you have to return
true lists.
Giving the func to the permutation function, you can avoid lot of list
copying and unpacking.
try:
import psyco
psyco.full()
except ImportError:
pass
d0, d1 = 1, 2
def func(p):
a0,a1,a2,b0,b1,b2,c0,c1,c2 = p
# do application evaluation here
b1b2 = 10*b1+b2
a1a2 = 10*a1+a2
c1c2 = 10*c1+c2
if d1*a0*b1b2*c1c2 + d1*b0*a1a2*c1c2 + d1*c0*a1a2*b1b2 \
== d0*a1a2*b1b2*c1c2:
return sorted( [[a0, a1, a2], [b0, b1, b2], [c0, c1, c2]] )
else:
return None
def accepted_permutations(alist, func):
# func must return None for the unacceptable results
# Algoritm from Phillip Paul Fuchs, modified
result = []
items = alist[:]
n = len(alist)
p = range(n+1)
i = 1
r = func(alist)
if r is not None: result.append(r)
while i < n:
p[i] -= 1
if i & 1:
j = p[i]
else:
j = 0
alist[j], alist[i] = alist[i], alist[j]
r = func(alist)
if r is not None: result.append(r)
i = 1
while p[i] == 0:
p[i] = i
i += 1
return result
def main():
result = []
for aresult in accepted_permutations(range(1, 10), func):
if aresult not in result:
result.append(aresult)
[[a0, a1, a2], [b0, b1, b2], [c0, c1, c2]] = aresult
print ' %0d %0d %0d %0d' % (a0, b0, c0, d0)
print '--- + --- + --- = ---'
print ' %0d%0d %0d%0d %0d%0d
%0d'%(a1,a2,b1,b2,c1,c2,d1)
print
main()
Bye,
bearophile
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