/*

*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. 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).

*/

class Solution {

public:

int threeSumClosest(vector<int>& nums, int target) {

int len = nums.size();

if(len <= 3)

return accumulate(nums.begin(),nums.end(),0);

sort(nums.begin(),nums.end());

int sum;

int res = nums[0]+nums[1]+nums[2];

for(int i = 0; i < len - 2; i++)

{

int j = i + 1;

int k = len -1;

while(j < k)

{

sum = nums[i]+nums[j]+nums[k];

if(abs(target - res) > abs(target -sum))

res = sum;

(sum > target)? k--:j++;

}

}

return res;

}

};