Write a program containing a function that outputs the elements stored in the tree (integers) to the screen. The integers have to be output level by level in the order they appear in the tree.
For example, if the tree stores numbers 3 2 6 4 7 1 5 as shown below, then the tree will have the following form:
3
/
2 6
/ /
1 4 7
5
Your program should produce an output like this:
3
2 6
1 4 7
5