Question:codility Lesson5 PassingCars
My answer:
def soluiton(A):
east = 0
pairs = 0
for i in xrange(len(A)):
#print i,A[i]
if A[i] == 0:
east += 1
elif A[i] == 1:
pairs += east
if pairs > 1000000000:
return -1
return pairs