摘要：
Let f(x) be the number of zeroes at the end of x!. (Recall that x! = 1 * 2 * 3 * ... * x, and by convention, 0! = 1.) For example, f(3) = 0 because 3! 阅读全文
摘要：
Given an integer n, return the number of trailing zeroes in n!. Example 1: Input: 3Output: 0Explanation: 3! = 6, no trailing zero.Example 2: Input: 5O 阅读全文
摘要：
Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n). Example: Input: S = "ADOB 阅读全文