LeetCode 16. 3Sum Closest(最接近的三数之和)

16. 最接近的三数之和
16. 3Sum Closest

题目描述
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.

LeetCode16. 3Sum Closest中等

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).

Java 实现

import java.util.Arrays;

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

    public static void main(String[] args) {
        int[] nums = {-1, 2, 1, -4};
        int target = 1;
        System.out.println(new Solution().threeSumClosest(nums, target));
    }
}

运行结果

2

相似题目

• 15. 三数之和 3Sum
• 259. 较小的三数之和 3Sum Smaller

参考资料

• https://leetcode-cn.com/problems/3sum-closest/
• https://leetcode.com/problems/3sum-closest/