Infix and Postfix

1. What does the push operation on a stack do?

a: Adds an element to the bottom of the stack. Explanation

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b: Adds an element to the top of the stack. Explanation

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c: Removes an element from the top of the stack. Explanation

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d: Adds an element in the middle of the stack. Explanation

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2. Situation: A teacher wants to process the operators in an arithmetic expression while temporarily remembering operators that cannot yet be placed in the output. Which approach best represents the use of a stack?

a: Teacher memorizes all operators without keeping any order. Explanation

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b: Teacher asks a favorite student to remember all operators and use them whenever needed. Explanation

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c: Teacher places each pending operator on top of a stack and removes the most recent applicable operator first. Explanation

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d: Teacher asks every student to remember every operator in the expression. Explanation

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3. Situation: A teacher wants to process an arithmetic expression using a stack. What is an important limitation of this approach?

a: It eliminates the need to consider operator precedence. Explanation

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b: Access to an arbitrary item in the stack is not the normal operation; stack access is restricted to the top. Explanation

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c: It requires all operands to be stored permanently in the stack. Explanation

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d: It makes every arithmetic expression invalid. Explanation

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4. Which of the following best describes a stack?

a: People standing in a queue at a service counter. Explanation

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b: A family tree. Explanation

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c: A football team. Explanation

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d: A set of dinner plates placed on top of one another. Explanation

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5. On what principle are objects inserted and removed in stacks?

a: LIFO Explanation

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b: FIFO Explanation

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c: LILO Explanation

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d: None of these Explanation

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6. Which notation places the operator between its operands, as in

a+b

a: Prefix notation Explanation

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b: Postfix notation Explanation

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c: Infix notation Explanation

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d: Reverse Polish notation Explanation

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7. Why is operator precedence important when converting an infix expression to postfix?

a: It determines the order in which operators should be placed in the postfix expression. Explanation

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b: It changes every operand into an operator. Explanation

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c: It removes all parentheses without considering operator relationships. Explanation

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d: It determines the variable names used in the expression. Explanation

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8. What is the main purpose of converting a valid infix expression to postfix notation?

a: To make the expression contain more operators. Explanation

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b: To represent the expression so that evaluation can proceed without relying on infix parentheses and precedence during evaluation. Explanation

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c: To change every operator into a unary operator. Explanation

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d: To guarantee that the expression contains only numbers. Explanation

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9. For the infix expression

a+b*c

, which relationship between the operators must be respected during conversion?

a: Addition must be performed before multiplication. Explanation

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b: Multiplication must be placed so that it is evaluated before addition. Explanation

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c: The operators must always be processed from right to left. Explanation

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d: Both operators have to be removed from the expression. Explanation

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