Given a binary tree, return the inorder traversal of its elements.
The first line contains an integer T denoting the number of test cases.
For each test case, the input has 2 lines:
For each test case, the output has a line containing the inorder traversal of the tree.
5
12
1 2 3 4 5 6 -1 -1 -1 7 -1 8
7
1 2 -1 4 -1 5 6
7
8 -1 9 -1 10 11 12
5
28 14 11 -1 48
1
6
4 2 7 5 1 8 6 3
5 4 6 2 1
8 9 11 10 12
14 48 28 11
6
1 <= T <= 10
1 <= n <= 105
1 <= node value <= 104