小纸条

摘要： 参考链接：https://www.cnblogs.com/Kohinur/p/8947142.html 链式前向星 vector存储 阅读全文

摘要： Given an integer n, return the number of trailing zeroes in n!. Example 1: Example 2: 题目问阶乘的结果有几个零，如果用笨方法求出阶乘然后再算 0 的个数会超出时间限制。 然后我们观察一下，5 的阶乘结果是 120， 阅读全文

摘要： Shuffle a set of numbers without duplicates. Example: 阅读全文

摘要： Given an array nums of n integers and an integer target, are there elements a, b, c, and d in nums such that a + b + c + d = target? Find all unique q 阅读全文

摘要： Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0? Find all unique triplets in the array which gives the s 阅读全文

摘要： Reverse a singly linked list. Example: Follow up: A linked list can be reversed either iteratively or recursively. Could you implement both? 阅读全文

摘要： Given a singly linked list, determine if it is a palindrome. Example 1: Example 2: Follow up:Could you do it in O(n) time and O(1) space? (1)定义快慢指针得到链 阅读全文

摘要： Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacen 阅读全文

摘要： Given a non-empty array of integers, return the k most frequent elements. Example 1: Example 2: Input: nums = [1], k = 1 Output: [1] 这个题目更加像是一道语法题目。。。 阅读全文

摘要： Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. (i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]). Y 阅读全文