You are asked to use C++ to implement

Binary Tree Traversal

AVL Tree Insertion and Deletion

Your submission should contain exactly one file: main.cpp You do not need to submit a design.

There are be different versions of AVL trees. You should implement one where you delete a node with two children, swap the value with the largest value on the left.

You should start your program by initializing an empty AVL tree. Your program takes one line as input. The input line contains n modification moves separated by spaces (1 n 100). The available modification moves are

Aint (Character A followed by an int value between 1 and 100): A3 means insert value 3 into the AVL tree. If 3 is already in the tree, do nothing.

Dint (Character D followed by an int value between 1 and 100): D3 means delete value 3 into the AVL tree. If 3 is not in the tree, do nothing.

Your input is then followed by exactly one finishing move (PRE or POST or IN): If the finishing move is PRE, then you should print out the tree (in its current situation) in pre-order. If the tree is empty, print out EMPTY. Otherwise, print out the values separated by spaces. POST and IN are handled similarly.

compile your code using g++ -o main.out -std=c++11 -O2 -Wall main.cpp

You dont need to worry about invalid inputs.

Sample input 1: A1 A2 A3 IN Sample output 1: 1 2 3

Sample input 2: A1 A2 A3 PRE Sample output 2: 2 1 3

Sample input 3: A1 D1 POST Sample output 3: EMPTY