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).
给定一个数组,从中找出三个数,使得三个数的和与目标值最接近。返回三个数的和
class Solution { public: int threeSumClosest(vector<int> &num, int target) { int result=0; int size=num.size(); if(size<3)return result; int minDiff=INT_MAX; int targetSum=0; sort(num.begin(), num.end()); //排序 for(int p1=0; p1<size-2; p1++){ if(p1!=0 && num[p1]==num[p1-1])continue; //第一个数排重 int p2=p1+1; int p3=size-1; while(p2<p3){ if(p2!=p1+1 && num[p2]==num[p2-1]){p2++;continue;} //第二个数排重 int sum=num[p1]+num[p2]+num[p3]; if((int)abs(sum-target)<minDiff){minDiff=(int)abs(sum-target); targetSum=sum;} if(sum>target)p3--; else if(sum<target)p2++; else return targetSum; } } return targetSum; } };
LeetCode 016 3Sum Closest,布布扣,bubuko.com
原文地址:http://blog.csdn.net/harryhuang1990/article/details/25962903