UGC NET CSE | December 2012 | Part 2 | Question: 40

Question

Given an empty stack, after performing push(1), push(2), pop, push(3), push(4), pop, pop, push(5), pop, what is the value of the top of the stack?

• A. 4
• B. 3
• C. 2
• D. 1

Answer 1

Operation	push(1)	push(2)	pop	push(3)	push(4)	pop	pop	push(5)	pop
					4
		2		3	3	3		5
	1	1	1	1	1	1	1	1	1

Hence,Option(D)1 is the correct choice.

Answer 2

Answer: 1

Push 1    Push 2

 1    Pop 2

1     Push 3    Push 4 

1     Pop 4     Pop 3

1     Push 5  

1     Pop 5

1    <=== Answer