Question

Which of the following is NOT an application of stack?

• A. Evaluation of Postfix expression
• B. Recursion
• C. Priority Queue
• D. Function calls

Hint:

Stack → LIFO, Queue → FIFO, Priority Queue → based on priority (heap).

Answer 1

The Correct Option is C

Concept: A stack is a linear data structure that follows LIFO (Last In First Out). Common applications of stack:
• Expression evaluation (Postfix/Prefix)
• Function calls (call stack)
• Recursion handling

Step 1: Analyze each option.
• A: Postfix evaluation → uses stack ✔
• B: Recursion → uses stack ✔
• C: Priority Queue → uses heap, not stack ✘
• D: Function calls → uses stack ✔

Step 2: Conclusion. Priority Queue is not related to stack. \[ \boxed{(3)} \]