Question

Given an integer n, return the number of trailing zeroes in n!.

Example 1:

Input: 3 Output: 0 Explanation: 3! = 6, no trailing zero.

Example 2:

Input: 5 Output: 1 Explanation: 5! = 120, one trailing zero.

Difficulty:Easy

Category:Math

Analyze

Solution

class Solution {
 public:
  int trailingZeroes(int n) {
    if (n < 5)
      return 0;
    else
      return n / 5 + trailingZeroes(n / 5);
  }
};