给定一个数组，求x和y，使得abs(x+y)最接近零

// 给定一个数组，求x和y，使得abs(x+y)最接近零
// 要求时间复杂度尽量小
// 先排序：

#include<stdio.h>
#include <algorithm>
#include <iostream>

using namespace std;
void getZeroPoint(int *p, int n, int&a,int &b)
{

	if (p[0] <=0 && p[n-1]<=0)
	{
		cout<<"非正数组"<<endl;
		a=p[n-2];
		b=p[n-1];
		return;
	}
	if (p[0]>=0 && p[n-1]>=0)
	{
		cout<<"非负数组"<<endl;
		a=p[0];
		b=p[1];
		return;
	}
	//////////////////////////////////////////////////////////////////////////
	int i=0, j=n-1;
	int sum=RAND_MAX;
	while (i<j)
	{
		cout<<"i: "<<i<<"     j: "<<j;
		if (p[i]+p[j]==0)
		{
			a=p[i];
			b=p[j];
			return;
		}
		if (abs(p[i]+p[j])<sum)
		{
			a=p[i];
			b=p[j];
			sum = abs(p[i]+p[j]);
		}
		cout<<"     "<<sum<<endl;
		if (abs(p[i]) > abs(p[j]))
		{
			i++;
		}
		else
		{
			j--;
		}
	}
}

int main()
{
	int p[10]={-5,3,1,11,-6,2,-20,67,8,9};
	//int p[10]={-5,-3,-1,-11,-6,-2,-20,-67,-8,-9};
	cout<<"原始数组："<<endl;
	copy(p,p+10,ostream_iterator<int>(cout," "));
	cout<<endl;


	cout<<"排序后的数组："<<endl;
	sort(p,p+10);
	copy(p,p+10,ostream_iterator<int>(cout," "));
	cout<<endl;

	cout<<endl<<"开始操作："<<endl<<"下标1    下标2     和"<<endl;
	int a,b;
	getZeroPoint(p,  10, a,b);
	cout<<"result:  "<<a<<" "<<b<<endl;

	return 0;
}

结果：