1.题目 26. Remove Duplicates from Sorted Array--Easy 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 modifyi…

描述 Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? 示例 Given sorted array nums = [1,1,1,2,2,3], Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3. It doesn't matte…

题目 Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? For example, Given sorted array nums = [1,1,1,2,2,3], Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3. It doe…

Given a sorted array nums, remove the duplicates in-place such that duplicates appeared at most twice 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 memo…

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 题解:最开始用了最naive的方法,每次在k个链表头中找出最小的元素,插入到新链表中.结果果断TLE了. 分析一下,如果这样做,每取出一个节点,要遍历k个链表一次,假设k个链表一共有n个节点,那么就需要O(nk)的时间复杂度. 参考网上的代码,找到了用最小堆的方法.维护一个大小为k的最小堆,存放当前k…

Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 题解:递归的枚举1~n的每个节点为根节点,…

1. Remove Duplicates from Sorted List 题目链接 题目要求: Given a sorted linked list, delete all duplicates such that each element appear only once. For example, Given 1->1->2, return 1->2. Given 1->1->2->3->3, return 1->2->3. 这道题不难.具体程序…

LeetCode 80 Remove Duplicates from Sorted Array II [Array/auto] <c++> 给出排序好的一维数组,如果一个元素重复出现的次数大于两次,删除多余的复制,返回删除后数组长度,要求不另开内存空间. C++ 献上自己丑陋无比的代码.相当于自己实现一个带计数器的unique函数 class Solution { public: int removeDuplicates(std::vector<int>& nums) {…

203题是在链表中删除一个固定的值,83题是在链表中删除重复的数值,但要保留一个:82也是删除重复的数值,但重复的都删除,不保留. 比如[1.2.2.3],83题要求的结果是[1.2.3],82题要求的结果是[1,3]. 这种题用递归去做比较方便思考,特别是这种重复的数值.递归就是只遍历当前的节点的情况,之前的不用管,之后的以当前节点为出发点思考问题. 203. Remove Linked List Elements class Solution { public: ListNode* remo…

题目 Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? For example, Given sorted array A = [1,1,1,2,2,3], Your function should return length = 5, and A is now [1,1,2,2,3]. 原题链接(点我) 解题思路 移除数组中反复次数超过2次以上出现的数,可是能够同意反复2次…