zeta(x)
that calculates the number of trailing zeroes in x!
by summing the integer division of x
by increasing powers of 5
.x
such that zeta(x) >= k
.x
such that zeta(x) <= k
.x
is greater than the largest x
, return 0
as there are no integers with exactly k
trailing zeroes.5
as there are exactly 5
integers with k
trailing zeroes.