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…

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…

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…

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…

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…

题目如下: 解题思路:本题和[leetcode]75. Sort Colors类似,但是没有要求在输入数组本身修改,所以难度降低了.引入一个新的数组,然后遍历输入数组,如果数组元素是是偶数,插入到新数组头部,否则追加到尾部. 代码如下: class Solution(object): def sortArrayByParity(self, A): """ :type A: List[int] :rtype: List[int] """ res =…

链接:https://leetcode.com/tag/sort/ [56]Merge Intervals (2019年1月26日,谷歌tag复习) 合并区间 Input: [[1,3],[2,6],[8,10],[15,18]] Output: [[1,6],[8,10],[15,18]] Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6]. 题解:先按照interval的begin从小到大s…

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…

Subsets II Given a collection of integers that might contain duplicates, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If S = [1,2,2], a so…

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 库函数排序 桶排序 红黑树排序 归并排序 快速排序 日期 题目地址:https://leetcode.com/problems/sort-an-array/ 题目描述 Given an array of integers nums, sort the array in ascending order. Example 1: Input: [5,2,3…

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 使用奇偶数组 排序 奇偶数位置变量 日期 题目地址: https://leetcode.com/problems/sort-array-by-parity-ii 题目描述 Given an array A of non-negative integers, half of the integers in A are odd, and half of…

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 字典 优先级队列 排序 日期 题目地址:https://leetcode.com/problems/sort-characters-by-frequency/description/ 题目描述 Given a string, sort it in decreasing order based on the frequency of character…

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 日期 题目地址:https://leetcode.com/problems/sort-list/description/ 题目描述 Sort a linked list in O(n log n) time using constant space complexity. Example 1: Input: 4->2->1->3 Output…

Sort a linked list using insertion sort. 思路: 用插入排序对链表排序.插入排序是指每次在一个排好序的链表中插入一个新的值. 注意:把排好序的部分和未排序的部分完全分开,指针不要有交叉. 即不会通过->next 重叠 class Solution { public: ListNode *insertionSortList(ListNode *head) { if(head == NULL) return NULL; ListNode * ans = hea…

Sort a linked list in O(n log n) time using constant space complexity. 链表排序可以用很多方法,插入,冒泡,选择都可以,也容易实现,但是复杂度不符合题意要求. 然后时间复杂度在O(nlogn)的排序算法中,堆排序,快速排序,归并排序. 堆排序,主要是基于数组的,这里是链表,实现起来比较麻烦. 快速排序,快速排序最坏情况的时间复杂度是O(n2) 归并排序,在对数组的归并排序中,是有O(n)的空间复杂度的,但是链表可以不需要,我们…

Valid Anagram Given two strings s and t, write a function to determine if t is an anagram of s. For example,s = "anagram", t = "nagaram", return true.s = "rat", t = "car", return false. Note:You may assume the strin…

Contains Duplicate Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct. 解法一: 排序,然后比较相邻元素是否相同…

Next Permutation Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers. If such arrangement is not possible, it must rearrange it as the lowest possible order (ie, sorted in ascending orde…

Maximum Gap Given an unsorted array, find the maximum difference between the successive elements in its sorted form. Try to solve it in linear time/space. Return 0 if the array contains less than 2 elements. You may assume all elements in the array a…

Wildcard Matching Implement wildcard pattern matching with support for '?' and '*'. '?' Matches any single character. '*' Matches any sequence of characters (including the empty sequence). The matching should cover the entire input string (not partia…

Surrounded Regions Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. For example, X X X X X O O X X X O X X O X X After running your function…

Combination Sum Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. The same repeated number may be chosen from C unlimited number of times. Note: All numbers (includi…

Single Number Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 解法一:用map记录每个元素的次数,返回次数为1的元素 cl…

Sort a linked list using insertion sort. //用到O(N)的额外空间 public class Solution { public ListNode insertionSortList(ListNode head) { if(head==null||head.next==null) return head; ListNode root = new ListNode(head.val); ListNode cur = head.next; while(cur…

题目如下: Given an array of integers nums, sort the array in ascending order. Example 1: Input: [5,2,3,1] Output: [1,2,3,5] Example 2: Input: [5,1,1,2,0,0] Output: [0,0,1,1,2,5] Note: 1 <= A.length <= 10000 -50000 <= A[i] <= 50000 解题思路:题目没说不能用系统函数…

Given a string s, sort it in decreasing order based on the frequency of the characters. The frequency of a character is the number of times it appears in the string. Return the sorted string. If there are multiple answers, return any of them. 考察了map的…

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 自定义sorted函数的cmp 日期 题目地址:https://leetcode.com/problems/sort-array-by-parity/description/ 题目描述: Given an array A of non-negative integers, return an array consisting of all the…

Counting Bits Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and return them as an array. Example:For num = 5 you should return [0,1,1,2,1,2]. Follow up…

Add Digits Given a non-negative integer num, repeatedly add all its digits until the result has only one digit. For example: Given num = 38, the process is like: 3 + 8 = 11, 1 + 1 = 2. Since 2 has only one digit, return it. Follow up:Could you do it…

Implement strStr() Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. 解法一:暴力解 class Solution { public: int strStr(string haystack, string needle) { int m = haystack.size();…