题目内容 Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution. For example, given array S = {…

kSum问题是一类问题,基本的方法是两个循环,其他一个查找,但是今天碰到了一个超级棘手的问题,是3Sum问题的一个变型 问题:给定一个数组,给定一个整数k,要求找出在数组中找到3个整数,使得这三个整数的和与k的相差最小! 思路:最受不了这种最大值最小值类的问题啦!如果是个确定的数还能通过一些二分查找.hash查找这样的方法来找,但是最大最小这类问题,需要自己处理找不到的情况!如果找不到这个值的话怎么办?那么我就在数组查找到这个target前后的两个值,然后比较一下即可! 编程: 1)lower_…

3Sum Closest Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution. For example, given arr…

3Sum Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero. Note: Elements in a triplet (a,b,c) must be in non-descending order. (ie, a ≤ b ≤ c) The…

1).2sum 1.题意:找出数组中和为target的所有数对 2.思路:排序数组,然后用两个指针i.j,一前一后,计算两个指针所指内容的和与target的关系,如果小于target,i右移,如果大于,j左移,否则为其中一个解 3.时间复杂度:O(nlgn)+O(n) 4.空间:O(1) 5.代码: void twoSum(vector<int>& nums,int numsSize,int target,vector<vector<int>>& two…

1. Two Sum 题目链接 题目要求: Given an array of integers, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than ind…

我现在在做一个叫<leetbook>的免费开源书项目,力求提供最易懂的中文思路,目前把解题思路都同步更新到gitbook上了,需要的同学可以去看看 书的地址:https://hk029.gitbooks.io/leetbook/ 16. 3Sum Closest [M] Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target.…

3sum Closest: Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution. For example, given ar…

算是经典算法问题了.这里主要针对只存在一个解或者只需要求一个解的情况描述一下解题思路.若需要找到所有可能解,方法需要略作调整.如有问题,欢迎指正. 2 sum: 如果已排序,可直接用夹逼法,即两指针从头尾向中间移动,使和靠近target.时间复杂度为O(n). 若未排序,因为除非有特别限制,比较排序的时间复杂度为O(nlgn).此时用hash更为合适,可以达到O(n)的时间复杂度.此方法实际上对已排序数组也实用.步骤如下: 每一个数a在放入hash表前,判断目标target-a是否在hash 表…

16. 3Sum Closest Total Accepted: 86565 Total Submissions: 291260 Difficulty: Medium Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume…