# ICT208 Algorithms and Data Structures Assessment 3: Recursion Case Study 2 Linked Lists- Case study 1 In this assessment, students will analyze a case and develop a solution by using recursive...

ICT208

Algorithms and Data Structures

Assessment 3: Recursion Case Study 2

 Linked Lists- Case study 1In this assessment, students will analyze a case and develop a solutionby using recursive functions and finally write code. Week 12 40% 1,2,3,4

Part A: Maze exploration using recursive function (30%)

A Maze is given as N*N binary matrix of blocks where source block is the upper left

most block i.e., maze[0][0] and destination block is lower rightmost block i.e., maze[N 1][N-1]. A rat starts from the source and has to reach the destination. The rat can move infour directions: left, right, up or down.

In the maze matrix, 0 means the block is a dead end and 1 means the block can be

used in the path from source to destination. Backtracking is an algorithmic technique
for solving problems recursively by trying to build a solution incrementally in mazeexploration.

Suggested Approach:

Form a recursive function, which will follow a path

and check if the path reaches the destination or not. If the path does not
reach the destination then backtrack and try other paths.

Algorithm:

1. Create a solution matrix, initially filled with 0’s.

2. Create a recursive function, which takes initial matrix, output matrix

and position of rat (i, j).

3. if the position is out of the matrix or the position is not valid then

return.

4. Mark the position output[i][j] as 1 and check if the current position is

destination or not. If destination is reached print the output matrix
and return.

5. Recursively call for position (i+1, j) and (i, j+1).

6. Unmark position (i, j), i.e output[i][j] = 0.

is to implement the given algorithm in C++ with recursive functions. You

need to test the solution in a main function by creating a 2D array and print out themaze solution correspondingly if there is a path existing. Your main program should have an option that allows the program to find a solution using either 2 way movement or 4 way movement.

There are a few existing websites for reference on maze exploration using recursion
for you:

https://www.geeksforgeeks.org/rat-in-a-maze-backtracking-2/

https://learn.saylor.org/mod/book/view.php?id=33001&chapterid=12855

.html

Part B: Huffman decoding using recursive functions (10%)

We have discussed Huffman encoding for data compression in lecture and tutorial,now we can implement the Huffman decoding for data extraction to recover theoriginal data.

To decode the encoded data, we require the Huffman tree. We iterate through the

binary encoded data. To find character corresponding to current bits, we use
following simple steps.

1. We start from root and do following until a leaf is found.

2. If current bit is 0, we move to left node of the tree.

3. If the bit is 1, we move to right node of the tree.

4. If during traversal, we encounter a leaf node, we print character of that

particular leaf node and then again continue the iteration of the encoded
data starting from step 1.

is to implement the Huffman decoding algorithm from the above steps in aC++ program with Huffman decoding function and a main function to decode acompressed string based on Huffman encoding and display the original string.

There are a few existing websites for reference on Huffman decoding algorithm for

you:

https://www.geeksforgeeks.org/huffman-decoding/

https://www.codespeedy.com/huffman-decoding-in-cpp/

https://www.programiz.com/dsa/huffman-coding

Submission requirement: upload the Mazz.cpp and Huffman.cpp to moodle by 5pm,June 3, 2022.

Marking rubric

 Marking criteria Lecturer expectation Marks Declaration of 2Darray in Mazz.cppmain function 2D array containscorrect data memberswith data types 10

 Backtracking of pathin a maze in 4- direction Backtrackingalgorithmsimplemented withrecursive functionscorrectly comments 45 Display the exploration path inMaze Maze path correctlyimplemented withcomments 20 Decode thecompressed Huffmancode successfully intree structure inHuffman.cpp Huffman decoding iscorrectlyimplemented withcomments 20 Display the completedecoded stringcorrectly inHuffman.cpp mainfunction Display is correctlyimplemented withcomments 5