[Project Euler] Problem 20

n! means n (n 1) ... 3 2 1

For example, 10! = 10 9 ... 3 2 1 = 3628800,
and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.

Find the sum of the digits in the number 100!

 

這個對於python來說實在太小兒科了。一句話的事：

print sum(int(x) for x in str(reduce(lambda x, y: x*y, range(1, 101))))