i-Blue的专栏

Given an integer n, return the number of trailing zeroes in n!. Note: Your solution should be in logarithmic time complexity. 重点在于质因数的运用。 一个数的阶乘可以写成其所有质数的n次方相乘的形式，例如： 10！= 2^8 * 3^4 *

Given an integer, write a function to determine if it is a power of three. Follow up: Could you do it without using any loop / recursion? 代码： class Solution { public: bool isPowerOfThree(i

题目以及解法思路答案在原网页上都有。https://leetcode.com/problems/count-primes/ Description: Count the number of prime numbers less than a non-negative number, n. Hint: Let's start with a isPrime function.