PAT1048

#include<stdio.h>
#include<algorithm>
using namespace std;

const int maxn=100010;
int n,m;
int value[maxn];

int binarySearch(int l,int r,int x)
{
	while(l<=r)
	{
		int mid=(r+l)/2;
		if(x==value[mid])
			return mid;
		else if(x>value[mid])
			l=mid+1;
		else
			r=mid-1;
	}
	return -1;
}

int main()
{
	//freopen("in.txt","r",stdin);
	scanf("%d%d",&n,&m);
	for(int i=0;i<n;i++)
		scanf("%d",&value[i]);
	sort(value,value+n);
	for(int i=0;i<n;i++)
	{
		if(value[i]>=m/2+1)
			break;
		int tmp=m-value[i];
		int index=binarySearch(i+1,n-1,tmp);//二分查找 
		if(index!=-1)
		{
			printf("%d %d\n",value[i],value[index]);
			return 0;
		}
	}
	printf("No Solution\n");
	return 0;
}

PAT1048

原文：http://blog.csdn.net/u014429500/article/details/44115235