fastest algorithm for factorial

general
, ,
1

which is best way for calculating factorial of a number n of more than 5 digit.

loop method:

s=1
for i in range(1,n+1):
    s*=i

recursion method:

def fact(n):
    if n==1 or n==0:
        return 1
    else:
        return n*fact(n-1)
2

from math import factorial

3

The loop will definitely be faster as it avoids the overhead of the function calls i.e.use of stack to store calling functions that are waiting for recursion to terminate. Infact i have sometimes noticed that replacing a function by code in the main part speeds up program by almost 2-3 times. Best way to analyse this would be to submit both codes and see their relative performance for the "small factorials " question in easy section.

1 Like
4

i wanted it for ‘factorial’ question in easy section

5

i had tried
import math math.factorial(), but when i calculate it for 100000 and above it take more time in python

6

What do you want?

7

link text

check for this one
for more help lokk in this tutorial here link text

1 Like
8

best algorithm for ‘factorial’ question ,so that my code doesn’t exceed the given time