Calculating no of trailing zeroes in factorial of given number

factorialTrailingZeroes.py #dailyCoding

def trailing_zeroes(n):
    # 0s are produced when 2 and 5 are multiplied
    # so you'll need to count how many 2s and 5s are there
    # 2s are always more than 5s so count just 5s
    res = 0
    k = 5
 
    # find all powers of 5
    # 25 has 2 5s, 125 has 3 5s, etc
    while k <= n:
        res += n // k
        k *= 5
 
    return res