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‎README.md

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| 11 | [Container With Most Water][011] | Array, Two Pointers |
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| 12 | [Integer to Roman][012] | Math, String |
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| 15 | [3Sum][015] | Array, Two Pointers |
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| 15 | [3Sum Closest][016] | Array, Two Pointers |
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| 17 | [Letter Combinations of a Phone Number][017] | String, Backtracking |
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| 19 | [Remove Nth Node From End of List][019] | Linked List, Two Pointers |
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| 33 | [Search in Rotated Sorted Array][033] | Arrays, Binary Search |
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[011]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/011/README.md
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[012]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/012/README.md
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[015]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/015/README.md
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[016]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/016/README.md
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[017]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/017/README.md
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[019]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/019/README.md
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[033]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/033/README.md

‎note/016/README.md

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# [3Sum Closest][title]
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## Description
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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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```
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For example, given array S = {-1 2 1 -4}, and target = 1.
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The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).
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```
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**Tags:** Array, Two Pointers
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## 思路
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这道题和 [3Sum][015] 的思路基本一样,先对数组进行排序,然后遍历这个排序数组,用两个指针分别指向当前元素的下一个和数组尾部,判断三者的和与 `target` 的差值来移动两个指针,并更新其结果,当然,如果三者的和直接与 `target` 值相同,那么返回 `target` 结果即可。
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```java
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public class Solution {
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public int threeSumClosest(int[] nums, int target) {
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int delta = 0x7fffffff, res = 0;
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Arrays.sort(nums);
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int len = nums.length - 2;
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for (int i = 0; i < len; i++) {
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int st = i + 1, end = nums.length - 1;
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while (st < end) {
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int sum = nums[i] + nums[st] + nums[end];
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int curDelta = Math.abs(sum - target);
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if (curDelta == 0) return sum;
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if (curDelta < delta) {
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delta = curDelta;
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res = sum;
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}
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if (sum > target) --end;
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else ++st;
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}
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}
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return res;
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}
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}
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```
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## 结语
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如果你同我一样热爱数据结构、算法、LeetCode,可以关注我 GitHub 上的 LeetCode 题解:[awesome-java-leetcode][ajl]
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[015]: https://github.com/Blankj/awesome-java-leetcode/blob/master/note/015/README.md
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[title]: https://leetcode.com/problems/3sum-closest
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[ajl]: https://github.com/Blankj/awesome-java-leetcode
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package com.blankj.medium._016;
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import java.util.Arrays;
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/**
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* <pre>
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* author: Blankj
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* blog : http://blankj.com
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* time : 2018年01月25日
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* desc :
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* </pre>
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*/
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public class Solution {
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public int threeSumClosest(int[] nums, int target) {
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int delta = 0x7fffffff, res = 0;
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Arrays.sort(nums);
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int len = nums.length - 2;
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for (int i = 0; i < len; i++) {
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int st = i + 1, end = nums.length - 1;
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while (st < end) {
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int sum = nums[i] + nums[st] + nums[end];
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int curDelta = Math.abs(sum - target);
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if (curDelta == 0) return sum;
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if (curDelta < delta) {
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delta = curDelta;
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res = sum;
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}
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if (sum > target) --end;
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else ++st;
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}
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}
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return res;
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}
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public static void main(String[] args) {
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Solution solution = new Solution();
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System.out.println(solution.threeSumClosest(new int[]{-1, 2, 1, -4}, 1));
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}
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}

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