Linear search using c++

#include<iostream>
using namespace std;
int lsearch(int a[],int n,int x)
{       int i;
    for(i=0;i<n;i++)
    {   if(a[i]==x)
        return i;
    }
    return -1;
}
int main()
{
     int n,x,i;
     int a[n];
   
     cout<<"Enter the size of  array";
     cin>>n;
    cout<<"Enter the elements of    array";
    for(i=0;i<n;i++)
    cin>>a[i];
    cout<<"The array you entered  is";
    for(i=0;i<n;i++)
    cout<<a[i]<<endl;
    cout<<"Enter the Element you want to find";
    cin>>x;
     int t=lsearch(a,n,x); 
     if(t==-1)
    cout<<"Element does not exist in the array";
    else
       {cout<<"The element exists    at index";
        cout<<t;
        }
   
}