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

这是我在逛 Stack Overflow 时遇见的一个高分问题:Why is processing a sorted array faster than an unsorted array?,我觉得这是一个非常好的用来讲分支预测(Branch Prediction)的例子,分享给大家看看 一.问题引入 先看这个代码: #include <algorithm> #include <ctime> #include <iostream> #include <stdint…

Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 思路:使用二分法,将list的中间节点作为根节点,然后分别处理list左半边及右半边,以此递归. struct TreeNode { int val; TreeNode *left; TreeNode *right; TreeNode(int x) : val(x), left(NULL), right…

Remove Duplicates from Sorted Array Given a sorted array, 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 in place with constant memory.…

重复一次 ［抄题］: 给定一个排序数组,在原数组中删除重复出现的数字,使得每个元素只出现一次,并且返回新的数组的长度. 不要使用额外的数组空间,必须在原地没有额外空间的条件下完成. ［思维问题］: ［一句话思路］: 不重复时,size扩大 ［输入量］:空: 正常情况:特大:特小:程序里处理到的特殊情况:异常情况(不合法不合理的输入): ［画图］: ［一刷］: ［总结］: ［复杂度］:Time complexity: O(n) Space complexity: O(1) ［英文数据结构,为什么不…

82. 删除排序链表中的重复元素 II 82. Remove Duplicates from Sorted List II 题目描述 给定一个排序链表,删除所有含有重复数字的节点,只保留原始链表中没有重复出现的数字. LeetCode82. Remove Duplicates from Sorted List II中等 示例 1: 输入: 1->2->3->3->4->4->5 输出: 1->2->5 示例 2: 输入: 1->1->1->…

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. Example 1: Input: 1->2->3->3->4->4->5 Output: 1->2->5 Example 2: Input: 1->1->1->2->3 Outpu…

Let's say we are going to find out number of occurrences of a number in a sorted array using binary search in O(log n) time. For example the given array is: [1,1,3,5,5,5,5,5,9,11], the number 5 appears 5 times; the number 3 appears 1 time; 2 appears…

Search in Rotated Sorted Array Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You are given a target value to search. If found in the array return its index, otherwise retu…

一:Search in Sorted Array 二分查找,可有重复元素,返回target所在的位置,只需返回其中一个位置,代码中的查找范围为[low,high),左闭右开,否则容易照成死循环. 代码: class Solution { public: int search(vector<int>& nums, int target) { int numsSize = nums.size(); ,high = numsSize; while(low < high){ ; if(n…