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:
1 class Solution { 2 public: 3 int threeSumClosest(vector<int>& nums, int target) {int result=0; 4 if(nums.size()<3) 5 return result; 6 sort(nums.begin(),nums.end()); 7 int gap=abs(nums[0]+nums[1]+nums[2]-target); 8 auto last=nums.end(); 9 for(auto i=nums.begin();i<last-2;i++) 10 { 11 auto j=i+1; 12 auto k=last-1; 13 while(j<k) 14 { 15 if(abs(*i+*j+*k-target)<=gap) 16 { 17 result=*i+*j+*k; 18 gap=abs(*i+*j+*k-target); 19 } 20 if((*i+*j+*k)<target) 21 j++; 22 else k--; 23 } 24 } 25 return result; 26 27 } 28 };
原文：http://www.cnblogs.com/riden/p/4631471.html