| 11|[Container With Most Water][011]| Array, Two Pointers|

| 12|[Integer to Roman][012]| Math, String|

| 15|[3Sum][015]| Array, Two Pointers|

| 15|[3Sum Closest][016]| Array, Two Pointers|

| 17|[Letter Combinations of a Phone Number][017]| String, Backtracking|

| 19|[Remove Nth Node From End of List][019]| Linked List, Two Pointers|

| 33|[Search in Rotated Sorted Array][033]| Arrays, Binary Search|

[011]:https://github.com/Blankj/awesome-java-leetcode/blob/master/note/011/README.md

[012]:https://github.com/Blankj/awesome-java-leetcode/blob/master/note/012/README.md

[015]:https://github.com/Blankj/awesome-java-leetcode/blob/master/note/015/README.md

[016]:https://github.com/Blankj/awesome-java-leetcode/blob/master/note/016/README.md

[017]:https://github.com/Blankj/awesome-java-leetcode/blob/master/note/017/README.md

[019]:https://github.com/Blankj/awesome-java-leetcode/blob/master/note/019/README.md

[033]:https://github.com/Blankj/awesome-java-leetcode/blob/master/note/033/README.md

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.

**Tags:** Array, Two Pointers

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。

publicclassSolution {

publicintthreeSumClosest(int[]nums,inttarget) {

int delta=0x7fffffff, res=0;

Arrays.sort(nums);

int len= nums.length-2;

for (int i=0; i< len; i++) {

int st= i+1, end= nums.length-1;

while (st< end) {

int sum= nums[i]+ nums[st]+ nums[end];

int curDelta=Math.abs(sum- target);

if (curDelta==0)return sum;

if (curDelta< delta) {

delta= curDelta;

res= sum;

}

if (sum> target)--end;

else++st;

}

}

return res;

}

}

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]

[015]:https://github.com/Blankj/awesome-java-leetcode/blob/master/note/015/README.md

[title]:https://leetcode.com/problems/3sum-closest

[ajl]:https://github.com/Blankj/awesome-java-leetcode

packagecom.blankj.medium._016;

importjava.util.Arrays;

publicclassSolution {

publicintthreeSumClosest(int[]nums,inttarget) {

intdelta =0x7fffffff,res =0;

Arrays.sort(nums);

intlen =nums.length -2;

for (inti =0;i <len;i++) {

intst =i +1,end =nums.length -1;

while (st <end) {

intsum =nums[i] +nums[st] +nums[end];

intcurDelta =Math.abs(sum -target);

if (curDelta ==0)returnsum;

if (curDelta <delta) {

delta =curDelta;

res =sum;

}

if (sum >target) --end;

else ++st;

}

}

returnres;

}

publicstaticvoidmain(String[]args) {

Solutionsolution =newSolution();

System.out.println(solution.threeSumClosest(newint[]{-1,2,1, -4},1));

}

}