n00m wrote:
> 62.5030784639
Maybe this one could save a few seconds, it works best when there are
multiple occurrences of the same value.
A.
from time import time
def freq(L):
D = {}
for x in L:
D[x] = D.get(x,0)+1
return D
def test():
t = time()
f = file('m4000.txt')
f.readline()
L = []
for line in f:
L.append(map(int,line.split()))
q,w,e,r = map(freq,zip(*L))
sch,h = 0,{}
for xk,xv in q.iteritems():
for yk,yv in w.iteritems():
if h.has_key(xk+yk):
h[xk+yk] += xv*yv
else:
h[xk+yk] = xv*yv
for xk,xv in e.iteritems():
for yk,yv in r.iteritems():
if h.has_key(-(xk+yk)):
sch += h[-(xk+yk)]*xv*yv
print sch
print time()-t
if __name__=='__main__':
test()
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