#include <string>
#include <stack>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;
int threeSumClosest(vector<int>& nums, int target) {
sort(nums.begin(), nums.end());
int len = nums.size();
int min = INT_MAX;
int res;
for (int i = 0; i < len; i++) {
int low = i + 1;
int high = len - 1;
while (low < high) {
int temp = target - nums[low] - nums[high]-nums[i];
if (abs(temp) < min) {
min = abs(temp);
res = nums[low] + nums[high] + nums[i];
//while (low < high && nums[low+1] == nums[low]) low++;
//while (low < high && nums[high-1] == nums[high]) high--;
}
if (temp > 0) low++;
else if (temp < 0) high--;
else return target;
}
while ((i + 1 < len) && nums[i] == nums[i + 1]) i++;
}
return res;
}
int main() {
vector<int> nums = {13,2,0,-14,-20,19,8,-5,-13,-3,20,15,20,5,13,14,-17,-7,12,-6,0,20,-19,-1,-15,-2,8,-2,-9,13,0,-3,-18,-9,-9,-19,17,-14,-19,-4,-16,2,0,9,5,-7,-4,20,18,9,0,12,-1,10,-17,-11,16,-13,-14,-3,0,2,-18,2,8,20,-15,3,-13,-12,-2,-19,11,11,-10,1,1,-10,-2,12,0,17,-19,-7,8,-19,-17,5,-5,-10,8,0,-12,4,19,2,0,12,14,-9,15,7,0,-16,-5,16,-12,0,2,-16,14,18,12,13,5,0,5,6 };
int target = -59;
int re = threeSumClosest(nums, target);
}
原文：http://www.cnblogs.com/hustlx/p/5250603.html