Data Structures MCQs with Answers
Practice important Data Structures MCQs with answers and explanations.
Chapter: 6
Q121:
Which operation in a linked list-based stack has constant time complexity?
A. push()
B. pop()
C. isEmpty()
D. All of the above
Correct Answer:
D
Chapter: 6
Q122:
How does the push() method work in a linked list-based stack?
A. Adds an element at the end
B. Removes an element at the start
C. Adds an element at the start
D. Shifts elements to the right
Correct Answer:
C
Chapter: 7
Q123:
What is the postfix expression of the infix expression A + B * C?
A. ABC*+
B. AB+C*
C. A*BC+
D. AB*C+
Correct Answer:
A
Chapter: 7
Q124:
In postfix expressions, where are the operators placed?
A. After operands
B. Before operands
C. Between operands
D. Outside operands
Correct Answer:
A
Chapter: 7
Q125:
In the postfix expression 6 2 3 + -, what is the result after evaluating the first operator?
A. 5
B. 4
C. 1
D. -1
Correct Answer:
C
Chapter: 7
Q126:
When converting an infix expression to postfix, which operator is handled first in the expression A + B * C?
A. +
B. *
C. -
D. /
Correct Answer:
B
Chapter: 7
Q127:
Which data structure is commonly used to evaluate postfix expressions?
A. Queue
B. Array
C. Stack
D. Linked List
Correct Answer:
C
Chapter: 7
Q128:
In evaluating the postfix expression 6 2 3 + -, what will be the value of the stack after applying the first operator +?
A. [1]
B. [5, 6]
C. [1, 5]
D. [5]
Correct Answer:
D
Chapter: 7
Q129:
How do you handle an operand in the provided postfix evaluation algorithm?
A. Add to postfix
B. Push to stack
C. Pop from stack
D. Evaluate it
Correct Answer:
B
Chapter: 7
Q130:
What is the main advantage of postfix notation over infix notation?
A. No parentheses
B. Easy to understand
C. Less operators
D. Faster evaluation
Correct Answer:
A
Chapter: 7
Q131:
Which of the following is a correct postfix conversion of the infix expression (A + B) * C?
A. AB+C*
B. ABC+*
C. A*BC+
D. AB+C*
Correct Answer:
D
Chapter: 7
Q132:
During the postfix expression evaluation, when an operator is encountered, what should be done?
A. Push to stack
B. Pop two operands
C. Add to postfix
D. Skip it
Correct Answer:
B
Chapter: 7
Q133:
In the algorithm for infix to postfix conversion, when an operand is encountered, where is it added?
A. Stack
B. Postfix string
C. Ignored
D. Prefix string
Correct Answer:
B
Chapter: 7
Q134:
In the expression 4+3*2 without parentheses, which operation is performed first according to the precedence rule?
A. Addition
B. Multiplication
C. Subtraction
D. None
Correct Answer:
B
Chapter: 7
Q135:
In the algorithm for infix to postfix conversion, what is the purpose of the second while loop at the end?
A. Add operands to postfix
B. Add operators to postfix
C. Add parentheses to postfix
D. Add all characters to postfix
Correct Answer:
B
Chapter: 7
Q136:
In the example of 6 2 3 + -, after applying -, what is the result?
A. 1
B. -1
C. 4
D. 2
Correct Answer:
A
Chapter: 7
Q137:
How is the precedence of operators managed during the infix to postfix conversion?
A. Using a precedence function
B. By ignoring it
C. Using a stack
D. Direct conversion
Correct Answer:
A
Chapter: 7
Q138:
When an operator in the stack has higher precedence than the current input operator during conversion, what is done with the operator in the stack?
A. It is popped
B. It is pushed back
C. It is swapped
D. It is ignored
Correct Answer:
A
Chapter: 7
Q139:
In the infix to postfix conversion, what is done when the end of the input is reached?
A. The stack is cleared
B. The expression is re-evaluated
C. The input is discarded
D. The program terminates
Correct Answer:
A
Chapter: 7
Q140:
In the provided algorithm, what is the primary function of the stack?
A. Store operands
B. Store operators
C. Evaluate expressions
D. Handle errors
Correct Answer:
B