Jussi Piitulainen, 16.06.2010 13:10:
Lie Ryan writes:
On 06/15/10 21:49, superpollo wrote:
goal (from e.c.m.): evaluate
1^2+2^2+3^2-4^2-5^2+6^2+7^2+8^2-9^2-10^2+...-2010^2, where each
three consecutive + must be followed by two - (^ meaning ** in
this context)
[...]
Probably bending the rules a little bit:
sum(x**2 - 8*x - 20 for x in range(1, 2010, 5))
536926141
another variation:
sum((x - 10) * (x + 2) for x in range(1, 2010, 5))
536926141
Gleefully bending the rules all the way:
536926141
536926141
Timeit:
100000000 loops, best of 3: 0.0148 usec per loop
Certainly the fastest solution so far.
Stefan
--
http://mail.python.org/mailman/listinfo/python-list
