#include "stdafx.h"

#include "iostream"
using namespace std;

//非递归查找
int HalfFind(int arr[],int size,int key)
{
 int low=0;
 int high=size-1;
 int mid=0;
 int result=-1;
 while (low<=high)
 { mid=(low+high)/2;
 if(key==arr[mid])
 {
 result=arr[mid];
 break;
 }
 else if(key>mid)
 low=mid+1;
 else
 high=mid-1;
 }
 return result;
}

//递归查找
int HalfFind(int arr[],int low,int high,int key)
{

if(low<=high)
 {

int mid=(low+high)/2;
 if(arr[mid]==key)
 {
 return arr[mid];

}
 else if(key>arr[mid])
 HalfFind(arr,mid+1,high,key);
 else
 HalfFind(arr,low,mid-1,key);
 }
 else
 return -1;
}
int main(int argc, _TCHAR* argv[])
{
 int test[10]={1,2,3,4,5,6,7,8,9,10};
 cout<<HalfFind(test,10,1)<<endl;
 cout<<HalfFind(test,0,9,1)<<endl;
 getchar();
 return 0;
}