leetcode --16. 3Sum Closest

题目：https://leetcode.com/problems/3sum-closest/description/

代码：class Solution {
public:
int threeSumClosest(vector<int>& nums, int target) {
if(nums.size() < 3) return 0;
sort(nums.begin(), nums.end());
int closet = nums[0]+nums[1]+nums[2];
for(int i =0;i<nums.size()-2;i++){
if(i>0&&nums[i]==nums[i-1]) continue;
int start = i+1,end = nums.size()-1;
while(start<end){
int sum = nums[i]+nums[start]+nums[end];
if(sum == target) return sum;
if(abs(target-closet)>abs(sum-target)){
closet = sum;
}
if(sum>target) end--;
if(sum<target) start++;
}
}
return closet;
}
};