LeetCode——3Sum Closest

最新推荐文章于 2021-07-02 14:12:25 发布

原创最新推荐文章于 2021-07-02 14:12:25 发布 · 160 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#java #leetcode

算法专栏收录该内容

83 篇文章

订阅专栏

本文深入解析了3SumClosest算法，旨在寻找数组中三个数的组合，使其总和最接近目标值。通过详细解释代码逻辑，展示了如何在数组中有效搜索并返回最接近目标的三数之和。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

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 exactly one solution.

Example:
Given array nums = [-1, 2, 1, -4], and target = 1.
The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).

解法

和3Sum这题相似，固定一个值后在它后面寻找合适的另外两个数字，本来准备多加一点判断条件提高代码的效率，但是思路不够清晰没写出来，以后再来改吧，如果有更好更清晰的代码欢迎在评论区贴出来一起学习。

public int threeSumClosest(int[] nums, int target) {
        int res=0;
        int diff=Integer.MAX_VALUE;
        Arrays.sort(nums);
        for(int i=0;i<nums.length-2;i++)
        {
        	int j=i+1,k=nums.length-1;
        	while(j<k)
        	{
        		int sum=nums[i]+nums[j]+nums[k];
        		if(sum==target)
        			return target;
        		else
        		{
        			if(diff>Math.abs(target-sum))
            			{
            				diff=Math.abs(target-sum);
            				res=sum;
            			}
        			if(sum<target)
        				j++;
        			else
        				k--;
        		}
        	}
        }
        return res;
    }

Runtime: 11 ms, faster than 71.58% of Java online submissions for 3Sum Closest.
Memory Usage: 38.1 MB, less than 38.82% of Java online submissions for 3Sum Closest.