Dharma Previous Years Solved Sample Placement Papers
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Process of inserting an element in stack is called ____________
a) Create
b) Push
c) Evaluation
d) Pop
Answer: b
Explanation: Push operation allows users to insert elements in the stack. If the stack is filled completely and trying to perform push operation stack – overflow can happen.
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Process of removing an element from stack is called __________
a) Create
b) Push
c) Evaluation
d) Pop
Answer: d
Explanation: Elements in the stack are removed using pop operation. Pop operation removes the topmost element in the stack i.e. last entered element.
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In a stack, if a user tries to remove an element from an empty stack it is called _________
a) Underflow
b) Empty collection
c) Overflow
d) Garbage Collection
Answer: a
Explanation: Underflow occurs when the user performs a pop operation on an empty stack. Overflow occurs when the stack is full and the user performs a push operation. Garbage Collection is used to recover the memory occupied by objects that are no longer used.
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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
Explanation: The stack is filled with 5 elements and pushing one more element causes a stack overflow. This results in overwriting memory, code and loss of unsaved work on the computer.
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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
Explanation: In stack data structure, elements are added one by one using push operation. Stack follows LIFO Principle i.e. Last In First Out(LIFO).
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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
Explanation: Data transfer between the two asynchronous processes uses the queue data structure for synchronization. The rest are all stack applications.
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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
Explanation: In the entire parenthesis balancing method when the incoming token is a left parenthesis it is pushed into stack. A right parenthesis makes pop operation to delete the elements in stack till we get left parenthesis as topmost element. 3 elements are there in stack before right parentheses comes. Therefore, maximum number of elements in stack at run time is 3.
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Consider the usual algorithm for determining whether a sequence of parentheses is balanced. Suppose that you run the algorithm on a sequence that contains 2 left parentheses and 3 right parentheses (in some order). The maximum number of parentheses that appear on the stack AT ANY ONE TIME during the computation?
a) 1
b) 2
c) 3
d) 4 or more
Answer: b
Explanation: In the entire parenthesis balancing method when the incoming token is a left parenthesis it is pushed into stack. A right parenthesis makes pop operation to delete the elements in stack till we get left parenthesis as topmost element. 2 elements are there before right parenthesis which is the maximum number of elements in stack at run time.
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What is the value of the postfix expression 6 3 2 4 + – *?
a) 1
b) 40
c) 74
d) -18
Answer: d