LeetCode Q172: Factorial Trailing Zeros

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

Note: Your solution should be in logarithmic time complexity.

Solution:

Zeros is produced by "5 x even number", so count how many 5s in each number.

	class Solution {
	public:
	int trailingZeroes(int n) {
	int ans=0;
	while (n>=5) {
	n/=5;
	ans+=n;
	}
	return ans;
	}
	};

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