X$1$X$1220$: Complete method countNodes

Define a recursive method countNodes$()$ that counts all the nodes in the tree. Returns the number of nodes.

Your Answer:

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int countNodes$($BinaryNode root$)$

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$\{$

Use these two interfaces to solve this problem.

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public interface QueueADT $\{$

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public void clear$()$;

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public boolean enqueue$($E it$)$;

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public E dequeue$()$;

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public E frontValue$()$;

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public int numElements$()$;

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public boolean isEmpty$()$;

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$\}$

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$$

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interface StackADT $\{$

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public void clear$()$;

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public boolean push$($E it$)$;

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public E pop$()$;

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public E topValue$()$;

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public int numElements$()$;

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public boolean isEmpty$()$;

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$\}$

Write a method to remove all of the elements from the 'queue' $($one by one$)$ and add them to a newly created stack $($use a StackArray$)$ and push the values in the stack. Return this stack. If queue is null, then just return an empty stack. Make sure you use the interfaces from above.