3Sum Closest

Question:

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.

Solution:

class Solution {
public:
    int threeSumClosest(vector<int>& nums, int target) {int result=0;
    if(nums.size()<3)
        return result;
    sort(nums.begin(),nums.end());
    int gap=abs(nums[0]+nums[1]+nums[2]-target);
    auto last=nums.end();
    for(auto i=nums.begin();i<last-2;i++)
    {
        auto j=i+1;
        auto k=last-1;
        while(j<k)
        {
            if(abs(*i+*j+*k-target)<=gap)
            {
                result=*i+*j+*k;
                gap=abs(*i+*j+*k-target);
            }
            if((*i+*j+*k)<target)
                j++;
            else k--;
        }
    }
    return result;
        
    }
};