Note: Try to solve this task without using recursion, since this is what you'll be asked to do during an interview.

Given a binary tree of integers t, return its node values in the following format:

• The first element should be the value of the tree root;
• The next elements should be the values of the nodes at height 1 (i.e. the root children), ordered from the leftmost to the rightmost one;
• The elements after that should be the values of the nodes at height 2 (i.e. the children of the nodes at height 1) ordered in the same way;
• Etc.

Example

For

t = {
    "value": 1,
    "left": {
        "value": 2,
        "left": null,
        "right": {
            "value": 3,
            "left": null,
            "right": null
        }
    },
    "right": {
        "value": 4,
        "left": {
            "value": 5,
            "left": null,
            "right": null
        },
        "right": null
    }
}

the output should be

solution(t) = [1, 2, 4, 3, 5].

This t looks like this:

     1
   /   \\
  2     4
   \\   /
    3 5

Input/Output

• [execution time limit] 3 seconds (java)

• [memory limit] 1 GB

• [input] tree.integer t

  Guaranteed constraints:

  0 ≤ tree size ≤ 104.

• [output] array.integer

  An array that contains the values at t's nodes, ordered as described above.