[LeetCode] 16. 3Sum Closest

传送门

Description

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.

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For example, given array S = {-1 2 1 -4}, and target = 1.   The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).

　　

思路

题意：给出一串整数值序列，求取最接近目标值的三个数的和

题解：按照3Sum的思路然后更新与目标值最接近的三个数的和

+ View Code?

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class Solution {     //22ms     public int threeSumClosest(int[] nums, int target) {         Arrays.sort(nums);         int res = 0,min = Integer.MAX_VALUE;         int len = nums.length;         for (int i = 0;i < len - 2;i++){             int goal = target - nums[i];             int left = i + 1,right = len - 1;             while (left < right){                 int sum = nums[i] + nums[left] + nums[right];                 if (sum == target){                     return sum;                 }                 if (Math.abs(target - sum) < min){                     res = sum;                     min = Math.abs(target - sum);                 }                 if (nums[left] + nums[right] < goal){                     left++;                 }else if (nums[left] + nums[right] > goal){                     right--;                 }             }         }         return res;     } }