793. Preimage Size of Factorial Zeroes Function
Description
Let f(x)
be the number of zeroes at the end of x!
. Recall that x! = 1 * 2 * 3 * ... * x
and by convention, 0! = 1
.
- For example,
f(3) = 0
because3! = 6
has no zeroes at the end, whilef(11) = 2
because11! = 39916800
has two zeroes at the end.
Given an integer k
, return the number of non-negative integers x
have the property that f(x) = k
.
Example 1:
Input: k = 0 Output: 5 Explanation: 0!, 1!, 2!, 3!, and 4! end with k = 0 zeroes.
Example 2:
Input: k = 5 Output: 0 Explanation: There is no x such that x! ends in k = 5 zeroes.
Example 3:
Input: k = 3 Output: 5
Constraints:
0 <= k <= 109
Solutions
Solution 1
1 2 3 4 5 6 7 8 9 10 11 |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 |
|