决战Leetcode: easy part(51-96)

本博客是个人原创的针对leetcode上的problem的解法,所有solution都基本通过了leetcode的官方Judging,个别未通过的例外情况会在相应部分作特别说明. 欢迎互相交流! email: tomqianmaple@gmail.com 后续更多的easy题已经不属于Top Interview Questions,所以现在就不集中精力去做了,只做到目前的100题左右. Palindrome Linked List Lowest Common Ancestor of a Bina…

决战Leetcode: easy part(1-50)

本博客是个人原创的针对leetcode上的problem的解法,所有solution都基本通过了leetcode的官方Judging,个别未通过的例外情况会在相应部分作特别说明. 欢迎互相交流! email: tomqianmaple@gmail.com Two Sum Reverse Integer Palindrome Number Roman to Integer Longest Common Prefix Valid Parentheses Merge Two Sorted Lists…

LeetCode解题录-51~100

[leetcode]51. N-QueensN皇后 Backtracking Hard [leetcode]52. N-Queens II N皇后 Backtracking Hard [leetcode]53. Maximum Subarray最大子数组和 Dynamic Programming Easy [leetcode]54. Spiral Matrix螺旋矩阵 Array Medium [leetcode]55. Jump Game青蛙跳(能否跳到终点) Greedy Medium…

LeetCode(Easy)--C++笔记

前言:这是关于LeetCode上面练习题C++的笔记,有些地方参考有网友的解题方法(可能有些参考没能注明,望谅解),如有需要改进的地方希望留言指教,多谢! 目录: ZigZag Conversion Reverse digits of an integer Implement atoi to convert a string to an integer Determine whether an integer is a palindrome Write a function to find th…

leetcode easy problem set

*勿以浮沙筑高台* 持续更新........ 题目网址:https://leetcode.com/problemset/all/?difficulty=Easy 1. Two Sum [4ms] 2. Reverse Integer [12ms] 题意:将一个32bit signed integer反转输出,如果反转之后超出32位补码范围 [-2^31,2^31-1],则输出0 思路:边取模边算结果,结果存longlong判界 3. Palindrome Number [112ms]…

[Leetcode easy]存些水题34、20、700

leetcode 34 最早出现和最后出现 class Solution { public int[] searchRange(int[] nums, int target) { int []ans={-1,-1} ; for(int i=0;i<nums.length;i++){ if(nums[i]==target){ ans[0]=i; break; } } for(int j=nums.length-1;j>=0;j--){ if(nums[j]==target){ ans[1]=j;…

LeetCode No.94,95,96

No.94 InorderTraversal 二叉树的中序遍历题目给定一个二叉树,返回它的中序遍历. 示例输入: [1,null,2,3] 1 \ 2 / 3 输出: [1,3,2] 进阶:递归算法很简单,你可以通过迭代算法完成吗? 思路代码 No.95 GenerateTrees 不同的二叉搜索树 II 题目给定一个整数 n,生成所有由 1 ... n 为节点所组成的二叉搜索树. 示例输入: 3 输出: [ [1,null,3,2], [3,2,null,1], [3…

归并排序(归并排序求逆序对数)--16--归并排序--Leetcode面试题51.数组中的逆序对

面试题51. 数组中的逆序对在数组中的两个数字,如果前面一个数字大于后面的数字,则这两个数字组成一个逆序对.输入一个数组,求出这个数组中的逆序对的总数. 示例 1: 输入: [7,5,6,4] 输出: 5 限制: 0 <= 数组长度 <= 50000 归并排序简介: 归并排序(MERGE-SORT)是建立在归并操作上的一种有效的排序算法,该算法是采用分治法(Divide and Conquer)的一个非常典型的应用. 将已有序的子序列合并,得到完全有序的序列:即先使每个子序列有序,再使子序列…

LeetCode 面试题51. 数组中的逆序对

面试题51. 数组中的逆序对题目来源:https://leetcode-cn.com/problems/shu-zu-zhong-de-ni-xu-dui-lcof/ 题目在数组中的两个数字,如果前面一个数字大于后面的数字,则这两个数字组成一个逆序对.输入一个数组,求出这个数组中的逆序对的总数. 示例 1: 输入: [7,5,6,4] 输出: 5 解题思路思路:归并排序归并排序使用了分治的思想,这个过程需要使用递归来实现.在分治算法递归实现中,每层递归会涉及三个步骤: 分解:将原问题分解…

leetcode刷题-95/96/98

题目95题给定一个整数 n,生成所有由 1 ... n 为节点所组成的二叉搜索树 . 示例: 输入:3输出:[ [1,null,3,2], [3,2,null,1], [3,1,null,null,2], [2,1,3], [1,null,2,null,3]]解释:以上的输出对应以下 5 种不同结构的二叉搜索树: 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 思路递归的思路,选出一个点为根节点,分别添加左子树和右子树实现 #…

Leetcode easy

1. Two Sum Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution. Example: Given nums = [2, 7, 11, 15], target = 9, Because nums[0] + n…

C# 写 LeetCode easy #14 Longest Common Prefix

14.Longest Common Prefix Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "". Example 1: Input: ["flower","flow","flight"] O…

C# 写 LeetCode easy #28 Implement strStr()

28.Implement strStr() Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Example 1: Input: haystack = "hello", needle = "ll" Output: 2 Example 2: Input: haystack…

C# 写 LeetCode easy #27 Remove Element

27. Remove Element Given an array nums and a value val, 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 by modifying the input array in-place with O(1) extra memor…

C# 写 LeetCode easy #26 Remove Duplicates from Sorted Array

26.Remove Duplicates from Sorted Array Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this by modifying the input…

C# 写 LeetCode easy #21 Merge Two Sorted Lists

21. Merge Two Sorted Lists Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. Example: Input: 1->2->4, 1->3->4 Output: 1->1->2->3->4->4 代…

C# 写 LeetCode easy #20 Valid Parentheses

20.Valid Parentheses Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: Open brackets must be closed by the same type of brackets. Open brackets must be…

C# 写 LeetCode easy #13 Roman to Integer

13.Roman to Integer Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, two is written as II in Roman numeral, just two one's added together. Twelve is writ…

C# 写 LeetCode easy #9 Palindrome Number

9.Palindrome Number Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward. Example 1: Input: 121 Output: true Example 2: Input: -121 Output: false Explanation: From left to right, it reads…

C# 写 LeetCode easy #7 Reverse Integer

7.Reverse Integer Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note:Assume we are dealing with an environment which could only stor…

C# 写 LeetCode easy #1 Two Sum

1.Two Sum Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice. Example: Given nums = [2,…

力扣Leetcode 面试题51. 数组中的逆序对 - 归并排序

在数组中的两个数字,如果前面一个数字大于后面的数字,则这两个数字组成一个逆序对.输入一个数组,求出这个数组中的逆序对的总数. 示例 1: 输入: [7,5,6,4] 输出: 5 限制: 0 <= 数组长度 <= 50000 题解思路这题结合示例一眼看去觉得太简单了直接暴力二重循环结果自然是超时.. 要不这题难度也不会是困难实际上是利用归并排序的性质推荐直接看官方题解视频的思路 class Solution { public: int reversePairs(vector<i…

LeetCode Top 100 Liked 点赞最高的 100 道算法题

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 公众号:负雪明烛本文关键词:刷题顺序,刷题路径,好题,top100,怎么刷题,Leetcode, 力扣,Python, C++, Java 大家好,相信很多朋友在刷题时,看到 LeetCode 的 2000 多道题目,有点手足无措,非常需要一个刷题的顺序和清单. 我整理了在 LeetCode(中文版)上点赞数前 100 的题目,这些的题目基本都在千赞以上,全部都是好题. 举个例子,1…

Leetcode 题解

Leetcode Solutions Language: javascript c mysql Last updated: 2019-01-04 https://github.com/nusr/leetcode # Problems Solutions Difficulty Acceptance Paid-Only 001 two-sum c,javascript Easy 39.69% No 002 add-two-numbers javascript Medium 30.01% No 007…