CUET PG MCA 2025 Previous Year Questions (PYQs) – Page 1 of 8

• Topological Sort → Can be done using DFS (by finishing times). ✅

• Strongly Connected Components (SCCs) → Kosaraju’s and Tarjan’s algorithms use DFS. ✅

• Solving Maze Problem → DFS is a valid approach to explore paths in a maze. ✅

• Finding minimum distance in an unweighted graph → This requires Breadth First Search (BFS), not DFS, because BFS ensures the shortest path in an unweighted graph. ❌

EEE-754 Floating-Point Standard (+0 vs −0)

• +0 and −0 are distinct bit patterns in IEEE-754.

• They differ only in the sign bit:

  • +0 → sign bit = 0, exponent = all 0s, mantissa = all 0s.

  • −0 → sign bit = 1, exponent = all 0s, mantissa = all 0s.

• The exponent and mantissa fields are identical (all zeros).

• Mathematically, +0 and −0 compare equal, but they behave differently in some operations (e.g., 1/(+0) = +∞, 1/(−0) = −∞).

• FCFS (First Come First Serve): Executes in the order processes arrive, no burst-time consideration.

• SJF (Shortest Job First): Picks the process with the least CPU burst time → minimizes average waiting time.

• Round Robin: Allocates equal time slices (quantum) cyclically, ignoring burst length.

• Priority Scheduling: Selects based on priority value, not burst time (though burst time can be used as a priority heuristic).

For a deadlock to occur in a system, the following Coffman’s conditions must all hold together:

1. Mutual Exclusion – At least one resource must be held in a non-shareable mode.

2. Hold and Wait – A process holding resources is waiting for additional resources.

3. No Preemption – Resources cannot be forcibly taken away; they are released only voluntarily.

4. Circular Wait – A closed chain of processes exists, each waiting for a resource held by the next process in the chain.

If even one of these is not satisfied, deadlock cannot occur.

Use of semaphores ✅

Because the Dining Philosopher problem is a classical synchronization problem, and it is solved using semaphores / monitors / mutex locks.

• Overlays → related to memory management, not correct.

• Mutual exclusion → is a requirement, but the standard answer in MCQs is semaphores.

• Bounded waiting → is a condition, not the actual solution technique.

So the correct choice from the given options is "Use of semaphores."