折半查找(C++)

#include <iostream>
using namespace std;
int BinSearch(int *a,const int x,const int n);
int main()
{
	int x[]={1,2,3,4,5,6,7,8,9,10};
	int q,num=7;
	q=BinSearch(x,num,10);
	if(q<0) cout<<"没找到"<<endl;
	  else cout<<"在x["<<q<<"]找到"<<num<<endl; 
	return 0;
}
int BinSearch(int *a,const int x,const int n)
{
	int left=0,right=n-1;
    while(left<=right)
    {
    	int middle=(left+right)/2;
    	if(x<a[middle]) right = middle-1;
    	else if(x>a[middle]) left=middle+1;
    	  else return middle ;
	}
	return -1;
}