欧拉计划(python) problem 20

Factorial digit sum

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!

python code:

import math

sqrt=math.sqrt

result=1

for i in range(1,101):

result*=i

temp=str(result)

result=0

k=len(temp)

for i in range(0,k):

result+=int(temp[i])

print(result)

time: <1s