两种解法 1)记录0和1的个数 然后按照记录的个数将0和1重新放入原数组,剩下的补2 2)双指针left,right left表示0~left-1都为0,即i之前都为0 right表示right+1~nums.length都为2,即j之后都为2 遍历原数组 a)遇到为0的就把当前nums[i]与nums[left]交换 b)遇到为2的就交换nums[i]&nums[right],注意,写代码的时候要考虑交换过来的nums[right]有可能是2,如果i正常迭代变成i+1,漏掉了nums[righ…

Given an array with n objects colored red, white or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, whit…

Given an array with n objects colored red, white or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, whit…

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, white, and bl…

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, white, and bl…

Given an array with n objects colored red, white or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, whit…

翻译 给定一个包括红色.白色.蓝色这三个颜色对象的数组.对它们进行排序以使同样的颜色变成相邻的,其顺序是红色.白色.蓝色. 在这里,我们将使用数字0.1和2分别来代表红色.白色和蓝色. 原文 Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, whit…

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, white, and bl…

Given an array with n objects colored red, white or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, whit…

解法一:计数排序:统计0,1,2 的个数 时间复杂度:O(n) 空间复杂度:O(k)    k为元素的取值范围, 此题为O(1) class Solution { public: void sortColors(vector<int>& nums) { ] = {}; //存放0,1,2三个元素的频率 ;i<nums.size();i++){ assert(nums[i] >= && nums[i]<=); //若不符合条件则报错 count[nums…

LeetCode 75. Sort Colors (python一次遍历,模拟三路快排) 题目分析: 本题需要实现数字只包含0,1,2的排序,并且要求一次遍历. 由于只用把数字隔离开,很容易想到快排的分割操作partition. 将三类数字隔离开,也就是模拟三路快排了. 解题思路 快排是选取哨兵p,将一段数组分成<p,=p,>p三类,并按这个顺序隔离开. 本题类似,哨兵为1,将一段数组分成0,1,2,即<1,=1,>1,并按这个顺序隔离开. 代码如下 class Solution:…

75. 颜色分类 75. Sort Colors 题目描述 给定一个包含红色.白色和蓝色,一共 n 个元素的数组,原地对它们进行排序,使得相同颜色的元素相邻,并按照红色.白色.蓝色顺序排列. 此题中,我们使用整数 0. 1 和 2 分别表示红色.白色和蓝色. 注意: 不能使用代码库中的排序函数来解决这道题. 每日一算法2019/6/2Day 30LeetCode75. Sort Colors 示例: 输入: [2,0,2,1,1,0] 输出: [0,0,1,1,2,2] 进阶: 一个直观的解决方…

  75. Sort Colors   给定一个具有红色,白色或蓝色的n个对象的数组,将它们就地 排序,使相同颜色的对象相邻,颜色顺序为红色,白色和蓝色. 这里,我们将使用整数0,1和2分别表示红色,白色和蓝色. 注意:  您不应该使用库的排序功能来解决此问题. 例: 输入: [2,0,2,1,1,0]输出: [0,0,1,1,2,2] 跟进: 一个相当直接的解决方案是使用计数排序的两遍算法.首先,迭代0,1,和2的数组计数,然后覆盖总数为0的数组,然后是1,然后是2. 你能想出一个只使用恒定空…

Question 75. Sort Colors Solution 题目大意: 给一个数组排序,这个数组只有0,1,2三个元素,要求只遍历一遍 思路: 记两个索引,lowIdx初始值为0,highIdx初始值为nums.length - 1,遍历数组,如果是2就与highIdx处元素互换且highIdx-,如果是0就与lowIdx处元素互换且lowIdx++,i++,还剩一种情况就是1了,执行i++,循环结束条件是i<=highIdx Java实现: public void sortColors…

LeetCode:Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending order, convert it to a height balanced BST 分析:找到数组的中间数据作为根节点,小于中间数据的数组来构造作为左子树,大于中间数据的数组来构造右子树,递归解法如下 /** * Definition for binary tree * struct…

一.题目说明 题目75. Sort Colors,给定n个整数的列表(0代表red,1代表white,2代表blue),排序实现相同颜色在一起.难度是Medium. 二.我的解答 这个是一个排序,还是简单的,代码如下: class Solution{ public: void sortColors(vector<int>& nums){ int num0=0,num1=0,num2=0; for(int i=0;i<nums.size();i++){ if(nums[i]==0)…

一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white a…

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 计数排序 双指针 日期 题目地址:https://leetcode.com/problems/sort-colors/description/ 题目描述 Given an array with n objects colored red, white or blue, sort them so that objects of the same col…

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, white, and bl…

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, white, and bl…

Sort Colors Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue. Here, we will use the integers 0, 1, and 2 to represent the color red, w…

题目描述 给定一个包含红色.白色和蓝色,一共 n 个元素的数组,原地对它们进行排序,使得相同颜色的元素相邻,并按照红色.白色.蓝色顺序排列. 此题中,我们使用整数 0. 1 和 2 分别表示红色.白色和蓝色. 注意:不能使用代码库中的排序函数来解决这道题. 示例: 输入: [2,0,2,1,1,0] 输出: [0,0,1,1,2,2] 进阶: 一个直观的解决方案是使用计数排序的两趟扫描算法.首先,迭代计算出0.1 和 2 元素的个数,然后按照0.1.2的排序,重写当前数组. 你能想出一个仅使用常…

题目如下: 解题思路:我的解题思路是遍历数组,遇到0删除该元素并插入到数组头部,遇到1则不处理,遇到2删除该元素并插入到数组尾部. 代码如下: class Solution(object): def sortColors(self, nums): """ :type nums: List[int] :rtype: void Do not return anything, modify nums in-place instead. """ inx…

本文始发于个人公众号:TechFlow,原创不易,求个关注 今天是LeetCode专题的44篇文章,我们一起来看下LeetCode的75题,颜色排序 Sort Colors. 这题的官方难度是Medium,通过率是45%,点赞2955,反对209(国际版数据),从这份数据上我们大概能看得出来,这题的难度不大,并且点赞远远高于反对,说明题目的质量很不错.事实上也的确如此,这题足够简单也足够有趣,值得一做. 题意 给定一个n个元素的数组,数组当中的每一个元素表示一个颜色.一共有红白蓝三种颜色,分别用…

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…

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 这道题是要求把有序链表转为二叉搜索树,和之前那道Convert Sorted Array to Binary Search Tree 将有序数组转为二叉搜索树思路完全一样,只不过是操作的数据类型有所差别,一个是数组,一个是链表.数组方便就方便在可以通过index直接访问任意一个元…

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 这道题是要将有序数组转为二叉搜索树,所谓二叉搜索树,是一种始终满足左<根<右的特性,如果将二叉搜索树按中序遍历的话,得到的就是一个有序数组了.那么反过来,我们可以得知,根节点应该是有序数组的中间点,从中间点分开为左右两个有序数组,在分别找出其中间点作为原中间点的左右两个子节点,这不就是是二分查找法的核…

Given two sorted integer arrays A and B, merge B into A as one sorted array. Note:You may assume that A has enough space (size that is greater or equal to m + n) to hold additional elements from B. The number of elements initialized in A and B are m …

我在Github上新建了一个解答Leetcode问题的Project, 大家可以参考, 目前是Java 为主,里面有leetcode上的题目,解答,还有一些基本的单元测试,方便大家起步. 题目: Given two sorted integer arrays A and B, merge B into A as one sorted array. Note:You may assume that A has enough space (size that is greater or equal…

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 原题链接:https://oj.leetcode.com/problems/convert-sorted-list-to-binary-search-tree/ 题目:给定一个有正序链表,将其转换成一个二叉搜索树. 思路:能够依照之前的数组的思路来做.即找到中间值.再左右递归建树…