AL-303 Data Structure and Algorithms - Dec 2025 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aExplain the classification of data structures in detail.
   How to answer

   • Definition and classification: primitive vs non-primitive, linear vs non-linear
   • Linear structures: array, linked list, stack, queue with examples
   • Non-linear structures: tree, graph with examples
   • Diagram of classification hierarchy
2. 7 Marks
   bDefine Abstract Data Types (ADT). Explain the different operations performed on data structures and describe the criteria for cost estimation.
   How to answer

   • Definition of Abstract Data Type (ADT)
   • Operations: traversal, insertion, deletion, searching, sorting, merging
   • Criteria for cost estimation: time complexity, space complexity
   • Example of ADT e.g. Stack/Queue
3. 7 Marks
   aDescribe the memory representation of a Singly Linked List. Write an algorithm to insert a node at a specific position in a linked list.
   How to answer

   • Memory representation: data part + next pointer, head pointer
   • Diagram of nodes with addresses
   • Algorithm to insert at position: traverse to pos-1, create node, adjust links
   • Edge cases: insertion at beginning/end, invalid position
4. 7 Marks
   bDefine Stack as an ADT. Explain the array and linked list implementation of stacks.
   How to answer

   • Define Stack ADT: LIFO, operations push, pop, peek
   • Array implementation: top index, overflow/underflow
   • Linked list implementation: top pointer, dynamic nodes
   • Comparison of both implementations
5. 7 Marks
   aExplain the algorithm to convert an Infix expression to a Postfix notation using a stack.
   How to answer

   • Precedence and associativity rules
   • Steps: scan infix, push operators, pop to output
   • Handling parentheses
   • Example conversion trace
6. 7 Marks
   bExplain the concept of Queue simulation with a real-world example.
   How to answer

   • Definition of queue: FIFO principle
   • Simulation concept: enqueue/dequeue modeling real queue
   • Real-world example e.g. ticket counter, printer queue
   • Operations and applications
7. 7 Marks
   aDefine a Binary Search Tree (BST). Explain the algorithms for In-order, Pre-order, and Post-order traversal with an example.
   How to answer

   • Definition of BST: left < root < right property
   • In-order algorithm: Left-Root-Right
   • Pre-order: Root-Left-Right and Post-order: Left-Right-Root
   • Example tree with traversal outputs
8. 7 Marks
   bWhat are AVL Trees? Explain the four types of rotations (LL, RR, LR, RL) used to balance an AVL tree.
   How to answer

   • Definition of AVL tree and balance factor
   • LL and RR single rotations with diagrams
   • LR and RL double rotations with steps
   • Balancing procedure after insertion/deletion
9. 7 Marks
   aDefine the following tree terminologies: Height, Depth, Degree of a node, and Forest.
   How to answer

   • Height: longest path to leaf; Depth: distance from root
   • Degree of node: number of children
   • Forest: collection of disjoint trees
   • Examples with small tree diagram
10. 7 Marks
    bExplain the Adjacency Matrix and Adjacency List representations of a graph.
    How to answer

    • Adjacency matrix: VxV matrix, 0/1 or weights
    • Adjacency list: array of lists for neighbours
    • Space/time comparison
    • Example graph with both representations
11. 7 Marks
    aDescribe the Depth First Search (DFS) and Breadth First Search (BFS) algorithms for graph traversal with examples.
    How to answer

    • DFS algorithm: recursion/stack, visit deep first
    • BFS algorithm: queue, level-by-level
    • Step-by-step trace on example graph
    • Time complexity and applications
12. 7 Marks
    bWhat is a Minimum Spanning Tree (MST)? Explain Kruskal's or Prim's algorithm to find the MST of a weighted graph.
    How to answer

    • Definition of MST and properties
    • Kruskal's steps: sort edges, union-find, avoid cycle
    • Prim's steps: grow tree from source with min edge
    • Example on weighted graph
13. 7 Marks
    aExplain the Quick Sort algorithm with suitable example.
    How to answer

    • Partition procedure and pivot selection
    • Recursive divide-and-conquer steps
    • Worked example with array partitions
    • Time complexity best/worst/average
14. 7 Marks
    bExplain Binary Search with an example.
    How to answer

    • Prerequisite: sorted array, low-high-mid pointers
    • Steps: compare mid, discard half iteratively
    • Example search trace
    • Time complexity O(log n)
15. 14 Marks
    Write short notes on any Two:

    1. a)Circular Linked Lists
    2. b)Linear Probing and Chaining
    3. c)B+ Trees
    4. d)Dijkstra's shortest path algorithm
    How to answer

    • For chosen two: definition and key properties
    • Diagram/structure and operations
    • Example or algorithm steps
    • Applications/advantages