Stack
1. Stack in Data Structure is -----
a) LILO
b) FIFO
c) None of these
d) LIFO
Answer: d
2. Process of inserting an element in stack is called -----
a) Create
b) Push
c) Evaluation
d) Pop
Answer: b
3. Process of inserting an element in stack is called -----
a) Create
b) Push
c) Evaluation
d) Pop
Answer: d
4. In a stack, if a user tries to remove an element from an empty stack is called -----
a) Underflow
b) Empty collection
c) Overflow
d) Garbage collection
Answer: a
5. Pushing an element into stack already having five elements and stack size of 5, then stack
becomes -----
a) Overflow
b) Crash
c) Underflow
d) User flow
Answer: a
6. Entries in a stack are “ordered”. What is the meaning of this statement?
a) A collection of stacks is sortable
b) Stack entries may be compared with the ‘<‘ operation
c) The entries are stored in a linked list
d) There is a Sequential entry that is one by one
Answer: d
7. Which of the following is not the application of stack?
a) A parentheses balancing program
b) Tracking of local variables at run time
c) Compiler Syntax Analyzer
d) Data Transfer between two asynchronous process
Answer: d
8. Consider the usual algorithm for determining whether a sequence of parentheses is balanced.
The maximum number of parentheses that appear on the stack AT ANY ONE TIME when
the algorithm analyzes: (()(())(()))?
a) 1
b) 2
c) 3
d) 4 or more
Answer: c
9. What data structure would you mostly likely see in non recursive implementation of a
recursive algorithm?
a) Linked List
b) Stack
c) Queue
d) Tree
Answer: b
10. The process of accessing data stored in a serial access memory is similar to manipulating
data on a ________
a) Heap
b) Binary Tree
c) Array
d) Stack
Answer: d
11. What is the result of the following operation?
Top (Push (S, X))
a) X
b) X+S
c) S
d) XS
Answer: a
12. Which data structure is used for implementing recursion?
a) Queue
b) Stack
c) Array
d) List
Answer: b
13. Which of the following statement(s) about stack data structure is/are NOT correct?
a) Linked List are used for implementing Stacks
b) Top of the Stack always contain the new node
c) Stack is the FIFO data structure
d) Null link is present in the last node at the bottom of the stack
Answer: c
14. void fun(int n)
{
Stack S; // Say it creates an empty stack S
while (n > 0)
{
push(&S, n%2);
n = n/2;
}
while (!isEmpty(&S))
printf("%d ", pop(&S)); // pop an element from S and print it
}
What does the above function do in general?
a) Prints binary representation of n in reverse order
b) Prints binary representation of n
c) Prints the value of Logn
d) Prints the value of Logn in reverse order
Answer: b
15. Which of the following is true about linked list implementation of stack?
a) In push operation, if new nodes are inserted at the beginning of linked list, then in pop
operation, nodes must be removed from end.
b) In push operation, if new nodes are inserted at the end, then in pop operation, nodes must
be removed from the beginning.
c) Both of the above
d) None of the above
Answer: d
16. Consider the following pseudocode that uses a stack
declare a stack of characters
while ( there are more characters in the word to read )
{
read a character
push the character on the stack
}
while ( the stack is not empty )
{
pop a character off the stack
write the character to the screen}
What is output for input "geeksquiz"?
a) geeksquizgeeksquiz
b) ziuqskeeg
c) geeksquiz
d) ziuqskeegziuqskeeg
Answer: b
17. declare a character stack
while ( more input is available)
{
read a character
if ( the character is a '(' )
push it on the stack
else if ( the character is a ')' and the stack is not empty )
pop a character off the stack
else
print "unbalanced" and exit
}
print "balanced"
Which of these unbalanced sequences does the above code think is balanced?
a) ((())
b) ())(()
c) (()()))
d) (()))()
Answer: a
18. Consider the following array implementation of stack:
#define MAX 10
Struct STACK
{
Int arr [MAX];
Int top = -1;
}
If the array index starts with 0, the maximum value of top which does not cause stack
overflow is?
a) 8
b) 9
c) 10
d) 11
Answer: a
