【leetcode】16. 3Sum Closest

/** * 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). */#include <iostream>#include <string>#include <vector>#include <algorithm>using namespace std;int threeSumClosest(vector<int>& nums, int target){    int len = nums.size();    int closest = INT_MAX;    int l = 0, r = 0;    int sum = 0;    for (int i = 0; i < len; i++)    {        l = i + 1;        r = len - 1;        while (l < r)        {            sum = nums[i] + nums[l] + nums[r];            if (closest == INT_MAX)                closest = sum;            else                closest = abs(sum - target) < abs(closest - target) ? sum : closest;            if (sum == target)            {                return target;            }            else if (sum < target)                l++;            else                r--;        }    }    return closest;}int main(){    vector<int> nums = { -1, 2, 1, -4 };    sort(nums.begin(), nums.end());    //-4 -1 1 2    cout << threeSumClosest(nums, 1);    system("pause");    return 0;}

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