题目地址
https://leetcode.com/problems/factorial-trailing-zeroes/description/
题目描述
172. Factorial Trailing Zeroes
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.
思路
最终尾随零的数量之和质因子中2和5的数量有关, 很容易想到质因子5的数量一定会比2少, 所以只需要算出n!的质因子5的数量即可.
关键点
代码
- 语言支持：Java
class Solution {
public int trailingZeroes(int n) {
int zeroCount = 0;
while (n > 0) {
n /= 5;
zeroCount += n;
}
return zeroCount;
}
}
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