Binary Search using recursion

#include<iostream>
using namespace std;
int binary();
int n;
int a[100];
int main()
{
 

 cout<<"enter the values";
 
 for(int i=0; i<n; i++)
 {
  cin>>a[i];
 }
 int j;
 cout<<"enter the value to be searched";
 cin>>j;
    binary(j,a[10],0,9);
    return 0;
 
}
int binary(int j, int a[10], int x, int y)
{
 int mid=(x+y)/2;
 if(j==a[mid])
 {
  return mid;
 }
 else if(j>a[mid])
 {
  x=mid+1;
  return binary(j,a[n],x,y);
 }
 else
 {
  y=mid-1;
  return binary(j,a[n],x,y);
 }
    }
}