1.堆排序 //大顶堆的构造,传入的i是父节点 void HeapAdjust(int k[],int p,int n) { int i,temp; temp = k[p]; * p; i <= n;i*=) //逐渐去找左右孩子结点 { //找到两个孩子结点中最大的 ]) i++; //父节点和孩子最大的进行判断,调整,变为最大堆 if (temp >= k[i]) break; //将父节点数据变为最大的,将原来的数据还是放在temp中, k[p] = k[i]; //若是孩子结点的数据更…

[题目] Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x. You should preserve the original relative order of the nodes in each of the two partitions. For example,Given 1->4->3-…

Given a singly linked list L: L0→L1→…→Ln-1→Ln, reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… You must do this in-place without altering the nodes' values. For example, Given {1,2,3,4}, reorder it to {1,4,2,3}. 这道链表重排序问题可以拆分为以下三个小问题: 1. 使用快慢指针来找到链表的中点,并将链表从中…

拓扑排序基础 拓扑排序用于解决有向无环图(DAG,Directed Acyclic Graph)按依赖关系排线性序列问题,直白地说解决这样的问题:有一组数据,其中一些数据依赖其他,问能否按依赖关系排序(被依赖的排在前面),或给出排序结果. 最常用解决拓扑排序问题的方法是Kahn算法,步骤可以概括为: . 根据依赖关系,构建邻接矩阵或邻接表.入度数组 . 取入度为0的数据(即不依赖其他数据的数据),根据邻接矩阵/邻接表依次减小依赖其的数据的入度 . 判断减小后是否有新的入度为0的数据,继续进行第2…

题库:LeetCode题库 - 中等难度 习题:网友收集 - zhizhiyu 此处应为一个简单的核心总结,以及练习笔记. 查找一个数“在不在”?桶排序理论上貌似不错. 回文问题 ----> [IR] Suffix Trees and Suffix Arrays 大数计算 ----> [Algorithm] Polynomial and FFT 公共部分 ----> 俩字符串的 “最长公共部分” (动态规划问题)----> [Optimization] Dynamic progra…

本文介绍LeetCode上有关栈.链表.堆和队列相关的算法题的考点,推荐刷题20道.具体考点分类如下图: 一.栈 1.数学问题 题号:85. 最大矩形,难度困难 题号:224. 基本计算器,难度困难 题号:975. 奇偶跳,难度困难 2.字符串或数组问题 题号:316. 去除重复字母,难度困难 题号:402. 移掉K位数字,难度中等 3.栈的设计和应用问题 题号:341. 扁平化嵌套列表迭代器,难度困难 题号:636. 函数的独占时间,难度中等 二.链表 1.排序问题 题号:23. 合并K个排序…

源代码地址:https://github.com/hopebo/hopelee 语言:C++ 301. Remove Invalid Parentheses Remove the minimum number of invalid parentheses in order to make the input string valid. Return all possible results. Note: The input string may contain letters other tha…

164. Maximum Gap 164. 最大间隔 Given an unsorted array, find the maximum difference between the successive elements in its sorted form. Return 0 if the array contains less than 2 elements. 给定一个未排序数组,找出该数组在有序形式时,连续元素之间最大的间隔. Example 1: Input: [3,6,9,1] Ou…

本文总结LeetCode上有动态规划的算法题,推荐刷题总数为54道.具体考点分析如下图: 1.中心扩展法 题号:132. 分割回文串 II,难度困难 2.背包问题 题号:140. 单词拆分 II,难度困难(最佳解法采用记忆化回溯) 题号:416. 分割等和子集,难度中等 题号:474. 一和零,难度中等 题号:638. 大礼包,难度中等(回溯法解决,分解为子问题,有动态规划的思路) 3.最短路径问题 矩阵空间,逆向动态规划 题号:174. 地下城游戏,难度困难 题号:312. 戳气球,难度困难,…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 按顺序构造字符串 排序 日期 题目地址:https://leetcode.com/problems/custom-sort-string/description/ 题目描述 S and T are strings composed of lowercase letters. In S, no letter occurs more than once.…

# 增强学习成果 有一个研究成果,在学习中传授他人知识和讨论是最高效的做法,而看书则是最低效的做法(具体研究成果没找到地址).我写LeetCode博客主要目的是增强学习成果.当然,我也想出名,然而不知道能否出名. # 给算法的新手们提供一种思考方式的参考 提前说明,本人也不是高手. 算法这个东西有点玄乎.很多新手(包括我)初期入门的时候都学的是<算法导论>,然而我并不觉得<算法导论>是一本学习算法很好的书. 我们设计算法的流程,并不是像<算法导论>那样,好像天生就知道这…

终于将LeetCode的免费题刷完了,真是漫长的第一遍啊,估计很多题都忘的差不多了,这次开个题目汇总贴,并附上每道题目的解题连接,方便之后查阅吧~ 477 Total Hamming Distance 44.10% Meidum 475 Heaters  30.20% Easy 474 Ones and Zeroes  34.90% Meidum 473 Matchsticks to Square  31.80% Medium 472 Concatenated Words 29.20% Hard…

Find the length of the longest substring T of a given string (consists of lowercase letters only) such that every character in T appears no less than k times. Example 1: Input: s = "aaabb", k = 3 Output: 3 The longest substring is "aaa"…

题目链接:Path Sum II | LeetCode OJ Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2],…

题目链接:Path Sum | LeetCode OJ Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11…

题目链接:Balanced Binary Tree | LeetCode OJ Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more tha…

题目链接:Same Tree | LeetCode OJ Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identical and the nodes have the same value. Tags: Depth-first Search 分析 很基本的一道深度优…

题目链接:Recover Binary Search Tree | LeetCode OJ Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Note: A solution using O(n) space is pretty straight forward. Could you devise a constan…

题目链接:Validate Binary Search Tree | LeetCode OJ Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right…

题目链接:Symmetric Tree | LeetCode OJ Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree is symmetric: 1 / \ 2 2 / \ / \ 3 4 4 3 But the following is not: 1 / \ 2 2 \ \ 3 3 Note: B…

题目链接:Sudoku Solver | LeetCode OJ Write a program to solve a Sudoku puzzle by filling the empty cells. Empty cells are indicated by the character '.'. You may assume that there will be only one unique solution. A sudoku puzzle... ...and its solution n…

题目链接:Valid Sudoku | LeetCode OJ Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules. The Sudoku board could be partially filled, where empty cells are filled with the character '.'. A partially filled sudoku which is valid. Note:…

题目链接:Populating Next Right Pointers in Each Node II | LeetCode OJ Follow up for problem "Populating Next Right Pointers in Each Node". What if the given tree could be any binary tree? Would your previous solution still work? Note: You may only u…

题目链接:Populating Next Right Pointers in Each Node | LeetCode OJ Given a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next; } Populate each next pointer to point to its next right node. If there is no next ri…

最近刷LeetCode比较频繁,就购买了官方的参考电子书 (CleanCodeHandbook),里面有题目的解析和范例源代码,可以省去非常多寻找免费经验分享内容和整理这些资料的时间.惊喜的是,里面的所有源代码都是用java语言写的. 接下来的一段时间里,我会将里面的大部分内容翻译成中文,再加上一些小y自己的解法和扩展内容,以博客的形式发在博客园.我想,这会是一件非常有趣的事情. 以下是翻译的前言部分,第1.4题以及其解析部分. 前言: 嗨,各位刷LeetCode的小伙伴们. 就像你们看到这本书…

2015年即将过去,最近在回顾和总结过去一年的工作经历,发现自己并不能算是一名合格的程序员. Google某前员工Lucida在文章<白板编程访谈——Why,What,How>当中写道: 程序员可以被分为两种: 先确认前条件/不变式/终止条件/边界条件,然后写出正确的代码 先编写代码,然后通过各种用例/测试/调试对程序进行调整,最后得到似乎正确的代码 我个人保守估计前者开发效率至少是后者的10倍,因为前者不需要浪费大量时间在编码-调试-编码这个极其耗时的循环上. 很不幸的是,我觉得自己应该被归…

一.问题描述 星期五的晚上,一帮同事在希格玛大厦附近的"硬盘酒吧"多喝了几杯.程序员多喝了几杯之后谈什么呢?自然是算法问题.有个同事说:"我以前在餐      馆打工,顾客经常点非常多的烙饼.店里的饼大小不一,我习惯在到达顾客饭桌前,把一摞饼按照大小次序摆好--小的在上面,大的在下面.由于我      一只手托着盘子,只好用另一只手,一次抓最上面的几块饼,把它们上下颠倒个个儿,反复几次之后,这摞烙饼就排好序了.我后来想,这实际上是个     有趣的排序问题:假设有n块大小不一…

Sept. 22, 2015 学一道算法题, 经常回顾一下. 第二次重温, 决定增加一些图片, 帮助自己记忆. 在网上找他人的资料, 不如自己动手. 把从底向上树的算法搞通俗一些. 先做一个例子: 9/22/2015 Go over one example to build some muscle memory about this bottom up, O(1) solution to find the root node in subtree function. Sorted List: 1…

Sept. 13, 2015 Spent more than a few hours to work on the leetcode problem, and my favorite blogs about this problems: 1. http://siddontang.gitbooks.io/leetcode-solution/content/tree/construct_binary_tree.html 2.http://blog.csdn.net/linhuanmars/artic…

The Hamming distance between two integers is the number of positions at which the corresponding bits are different. Now your job is to find the total Hamming distance between all pairs of the given numbers. Example: Input: 4, 14, 2 Output: 6 Explanat…