This exercise is to be completed during your week 5 laboratory class. When you complete the exercise show your work to your lab tutor to have your work marked. The marking is based mainly on correct implementation and code readability. You should implement your code in one file (e.g. ex4.cpp, ex4.c, ex4.java). Make sure your program has a header comment block containing the name of the exercise, your name and your student login (e.g. jfk01). You may implement your solution in C, C++, java or Python.
For this exercise, you are to implement BST sort and test it for correctness. Your program should prompt for the name of an input file and then read and process the data contained in this file.
The file contains a sequence of integer values. Read them and construct a binary search tree from the values in the order they are read. Thus, the first number read will be the root of the tree. For this exercise, you may use dynamic data, as shown with the pseudo code on page 2.
You do not need to balance the tree as you construct it.
When you have read the last value into the BST, conduct an inorder traversal to output the values in ascending order.
Print the values 10 to a line in a 5character wide field.
Do not use STL or other libraries to implement the BST.
When you are finished, test your program using the provided text file named ex4.txt and show your code and the output to your lab tutor to receive your mark. Also, submit your file via unix (banshee) using the submit command below.
$ submit -u login -c CSCI203 a ex4 filename
where login is your UNIX login ID and filename is the name of your file.
If you are unable to attend your lab class and demonstrate your work on time due to circumstances beyond your control (e.g. sickness), contact your lecturer to request an extension.
BST Pseudo Code (from the week 4 lecture notes)
type tree_node = record
contents: stuff left: ^tree_node
right: ^tree_node
root: tree_node
procedure find(value: stuff, node: ^tree_node): ^tree_node if value == nil then
return not found
fi
if value == node.contents then
return node
else if value < node.contents then find(value, node.left)
else
find(value, node.right) fi end
| procedure insert(value: stuff, node: ^tree_node) | ||
| next: ^tree_node, left: boolean | ||
| if value == node.contents then | ||
| return | // already in the tree | |
| else if value < node.contents then | ||
| next = node.left; left= true | // we need to go left | |
| else | ||
| next = node.right; left = false | // we need to go right | |
| fi | ||
| if next != nil then | ||
| insert (value, next) | // keep trying | |
| else | ||
| next = new_tree_node | // make a new node | |
| next.contents = value | // store the value | |
| if left then | // update the parent | |
| node.left = next | ||
| else | ||
| node.right = next | ||
| fi | ||
| end | fi | |
procedure insert_first(value): ^tree_node
node: ^tree_node start = new_tree_node start.contents = value
return start
end
procedure visit(node: ^tree_node)
if node.left != nil then visit(node.left) fi
print(node.contents)
if node.right != nil then visit(node.right)
fi
return end
procedure main()
root: ^tree_node
open file & print error if file not found
read item
root = insert_first(item)
for each item in file insert(item, root)
visit(root)
end
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