Weak test cases for this problem - left view of binary tree

programming
Tags: #<Tag:0x00007f181c3c2a40>
#1

There are weak test cases for this problem.

Input : 9 1 2 3 -1 -1 -1 4 -1 -1
Expected result : 1 2 4
My wrong code gives : 1 2 and it gets accepted.

Please check.
Thanks.