OJ补写二分查找

#include <iostream>

using namespace std;
void input(int a[],int n)
{

    for(int i=0; i<n; i++)
        cin>>a[i];
}
int binsearch(int a[],int n,int value)
{
    int high=n-1,low=0,mid;

    while(low<=high)
    {
        mid=(high+low)/2;
        if(a[mid]==value)
            return mid+1;
        if(a[mid]>value)
           low=mid+1;
        else

    high=mid-1;
    }

    return 0;
}
int main()
{
    int a[20],n=0,value;
    int position;
    cin>>n;
    input(a,n);
    cin>>value;
    position =binsearch(a,n,value);
    cout<<position;
    return 0;
}