CODEBHAVYA · MODEL · OPERATE · ANALYSE

Data Structures

Data Structures in Real Systems

Learn why a structure is chosen, which invariants keep it correct, how every operation changes state and when another structure becomes the better engineering choice.

3Complete systems
4Core structures applied
35+Trace and test paths
C11Warning-clean programs

Case Study Library

Each project connects abstract operations to business behaviour, invariants, edge cases, complexity and interview-level design decisions.

CASE STUDY 01Intermediate

Browser History & Navigation

Model Back, Forward and Visit using a doubly linked list, including the subtle rule that visiting after Back deletes the abandoned forward branch.

Doubly Linked ListBidirectional TraversalDeletionOwnershipState Machine
Key invariantprevious/next symmetry
Main cursorcurrent page
Critical edgebranch deletion
Study Browser History →
CASE STUDY 02Advanced

Hospital Emergency Queue

Implement a stable priority queue where clinical urgency outranks arrival time while patients of equal priority remain first-come, first-served.

Priority QueueStable OrderingSorted InsertionDynamic MemoryTriage Rules
Key invariantpriority then arrival
Main pointerfront patient
Critical edgeequal priorities
Study Emergency Queue →
CASE STUDY 03Advanced

Expression Calculator

Convert infix expressions to postfix and evaluate them using separate operator and value stacks with full precedence, associativity and error handling.

StacksParsingPostfixPrecedenceAssociativityValidation
Key invariantvalid token order
Main structuresoperator + value stacks
Critical edgeright-associative ^
Study Expression Calculator →

The data-structure decision process

1

Identify operations

List which actions must be fast and which are occasional.

2

Define invariants

State what must remain true after every operation.

3

Trace pointers

Follow ownership and links before writing implementation code.

4

Challenge the choice

Compare arrays, stacks, queues, lists, heaps and indexed alternatives.