Corresponding Java Solution, Thanks it was easy to understand :).

static int count=0;

void top_view(Node root){

if(root.left!=null && count>=0){
    count++;
    top_view(root.left);
}

System.out.print(root.data+ " ");
count--;

if(root.right!=null && count<0){
    count--;
    top_view(root.right);

}

}