Given an m x n matrix board containing 'X' and 'O', capture all regions that are 4-directionally surrounded by 'X'.
m x n
board
'X'
'O'
Reverse bits of a given 32 bits unsigned integer.
Note:
Given an integer n, return the number of trailing zeroes in n!.
n
n!
Note that n! = n * (n - 1) * (n - 2) * ... * 3 * 2 * 1.
n! = n * (n - 1) * (n - 2) * ... * 3 * 2 * 1
Example 1:
Input: n = 3Output: 0Explanation: 3! = 6, no trailing zero.