LeetCode 3Sum Closest 最近似的3sum（2sum方法）

题意：找到最接近target的3个元素之和，并返回该和。

思路：用2个指针，时间复杂度O（n^2）。

 1 int threeSumClosest(vector<int>& nums, int target) {
 2     int sum=nums[0]+nums[1]+nums[2];
 3     sort(nums.begin(), nums.end());
 4     for(int i=0; i<nums.size()-2; i++)
 5     {
 6         int p=i+1, q=nums.size()-1;
 7         while( p!=q )
 8         {
 9             int tmp=target-(nums[i]+nums[p]+nums[q]);
10             if(abs(tmp)<abs(sum-target) )    sum=nums[i]+nums[p]+nums[q];
11             if(!tmp)    return target;
12             if(tmp>0)    p++;
13             else        q--;
14         }
15     }
16     return sum;
17 }

AC代码

时间： 2024-10-13 10:53:54

LeetCode 3Sum Closest 最近似的3sum（2sum方法）的相关文章

leetCode 16.3Sum Closest (离给定值最近的三数之和) 解题思路和方法

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

2Sum,3Sum,4Sum,kSum,3Sum Closest系列

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

3Sum Closest leetcode java

题目: 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 = {-

[LeetCode][JavaScript]3Sum Closest

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

LeetCode 016 3Sum Closest

[题目] 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 = {

[leetcode]3Sum Closest @ Python

原题地址:http://oj.leetcode.com/problems/3sum-closest/ 题意:数组中每三个元素进行求和,找出所有和中大小最接近target的和,并返回这个和与target之间的差值. 解题思路:使用一个变量mindiff来监测和与target之间的差值,如果差值为0,直接返回sum值. 代码: class Solution: # @return an integer def threeSumClosest(self, num, target): num.sort()

leetcode 3Sum 3Sum Closest 4Sum

这几个题很典型也是国外一些知名公司经常会问到的题 3Sum: 排序,避免重复,时间复杂度O(n^2) class Solution { public: vector<vector<int> > threeSum(vector<int> &num) { int len=num.size(); sort(num.begin(),num.begin()+len); vector<vector<int> > ret; ret.clear(); i

LeetCode[Array]----3Sum Closest

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

Leetcode 16. 3Sum Closest（指针搜索）

16. 3Sum Closest Medium 131696FavoriteShare Given an array nums of n integers and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of the three integers. You may assume that each input would have e