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.
Example
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).
解題思路
本題是3sum的變種題，基本思路一致。代碼如下：
class Solution {
public:
int threeSumClosest(vector<int>& nums, int target) {
sort(nums.begin(),nums.end());
int number = nums.size();
int res = nums[0] + nums[1] + nums[2];
for(int i = 0; i < number - 2; ++i)
{
int l = i + 1, r = number - 1;
while(l < r)
{
int num = nums[i] + nums[l] + nums[r];
if(abs(num - target) < abs(res - target))
res = num;
if(num < target)
l++;
else
r--;
}
}
return res;
}
};
