python 3                                                                                                                       
def topView(root):                                                                                             
    queue=[]                                                                                                       
    top_view={}                                                                                                   
    queue.append([root,0])                                                                              
    while(queue):                                                                                               
        node,level=queue.pop(0)  # to remove front element                       
        if level not in top_view:                                                                           
            top_view[level]=node.info                                                                                                                     
        if node.left:
            node.left.level=level-1
            queue.append((node.left, level - 1))
        if node.right:
            node.right.level=level+1
            queue.append((node.right, level + 1))
    print(top_view)
    for level in sorted(top_view):
        print(top_view[level],end=" ")