这道题是LeetCode里的第38道题. 题目要求: 报数序列是一个整数序列,按照其中的整数的顺序进行报数,得到下一个数.其前五项如下: 1. 1 2. 11 3. 21 4. 1211 5. 111221 1 被读作  "one 1"  ("一个一") , 即 11.11 被读作 "two 1s" ("两个一"), 即 21.21 被读作 "one 2",  "one 1" (&quo…

The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11.11 is read off as "two 1s" or 21.21 is read off as "one 2, then one 1" or 1211. Given an…

Count the number of prime numbers less than a non-negative number, n 思路:数质数的个数 开始写了个蛮力的,存储已有质数,判断新数字是否可以整除已有质数.然后妥妥的超时了(⊙v⊙). 看提示,发现有个Eratosthenes算法找质数的,说白了就是给所有的数字一个标记,把质数的整数倍标为false,那么下一个没被标为false的数字就是下一个质数. int countPrimes(int n) { ) ; bool * mark…

The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11.11 is read off as "two 1s" or 21.21 is read off as "one 2, then one 1" or 1211. Given an…

[LeetCode]222. Count Complete Tree Nodes 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/count-complete-tree-nodes/description/ 题目描述: Given a complete binary tree, count the n…

[LeetCode]Minimum Depth of Binary Tree Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. 递归和非递归,此提比较简单.广度优先遍历即可.关键之处就在于如何保持访问深度. 下面是4种代码: im…

27. Remove Element[leetcode] Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant memory. The order of elements can b…

题目如下: 解题思路:本题是[leetcode]473. Matchsticks to Square的姊妹篇,唯一的区别是[leetcode]473. Matchsticks to Square指定了分成四个子数组,而本题分成的份数不定,作为参数输入.另外,本题的测试用例好像复杂一点,因此我过滤掉了nums中值等于avg的元素,不参与后面的DFS计算,提高效率. 代码如下: class Solution(object): def canPartitionKSubsets(self, nums,…

[600] Non-negative Integers without Consecutive Ones [629] K Inverse Pairs Array [638] Shopping Offers [639] Decode Ways II [646] Maximum Length of Pair Chain [647] Palindromic Substrings 给定一个字符串,判断有多少子串是 palindromic 的,子串就算所有字母都相同,但是开始和结束位置的下标不同,也算不同…

链接:https://leetcode.com/tag/binary-search-tree/ [220]Contains Duplicate III (2019年4月20日) (好题) Given an array of integers, find out whether there are two distinct indices i and j in the array such that the absolute difference between nums[i] and nums[…