二分搜索代码（c++)

#include<iostream>
using namespace std;

template<typename Type>
int BinarySearch(Type a[],const Type& x,int n)   //&x是引用型
{
    int left=0,right=n-1;
    int num=0;                      //测试
    while(left<=right)
    {
        int middle=(left+right)/2;
        cout<<"第"<<++num<<"次："<<middle<<endl;        //测试
        if(x==a[middle])return middle;
        if(x>a[middle])left=middle+1;
        else right=middle-1;
    }
    return -1;
}

int main()
{
    int a[10]={0,1,2,3,4,5,6,7,8,9},result;
    int x;
    do{
    cout<<"（输入-1结束）请输入要二分搜索的数：";
    cin>>x;
    result=BinarySearch(a,x,10);
    if(result!=-1)
    {
        cout<<"存在数："<<x<<endl;
    }
    else
    {
        cout<<"不存在数："<<x<<endl;
    }
    }while(x!=-1);
    return 0;
}