A positive integer D is a factor of a positive integer N if there exists an integer M such that N = D * M.
For example, 6 is a factor of 24, because M = 4 satisfies the above condition (24 = 6 * 4).
Write a function:
class Solution { public int solution(int N); }
that, given a positive integer N, returns the number of its factors.
For example, given N = 24, the function should return 8, because 24 has 8 factors, namely 1, 2, 3, 4, 6, 8, 12, 24. There are no other factors of 24.
Assume that:
N is an integer within the range [1..2,147,483,647]. Complexity:
expected worst-case time complexity is O(sqrt(N)); expected worst-case space complexity is O(1).