Level Order Traversal of Binary Tree

Given a binary tree of integers, return its level order traversal.

Input:

The first line contains an integer 'T' which represents the number of test cases. For each test case, provide the elements of the tree in level order, separated by a single space. Use -1 to represent null nodes.

Output:

For each test case, print the nodes in level order traversal, separated by spaces, on a new line.

Example:

Input:

1
1 2 3 4 -1 5 6 -1 7 -1 -1 -1 -1 -1 -1

Output:

1 2 3 4 5 6 7

Explanation:

The input corresponds to the binary tree depicted in the provided image. The level order traversal starts from the root node and visits nodes level by level.

Constraints:

• 1 <= T <= 100
• 0 <= N <= 1000
• 0 <= data <= 10⁶ and data != -1
• Where 'T' is the number of test cases, 'N' is the number of nodes, and 'data' is the node's value.

Note: The sequence is single-line input for each test case, and you do not need to print anything explicitly.