Software-Engineering
December 26, 2023Relational-databases
December 26, 2023Queues-and-Stacks
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Question 17
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A stack is implemented with an array of ‘A [0…N-1]’ and a variable ‘pos’. The push and pop
operations are defined by the following code.
push(x)
A[pos] x
pos pos+1
end push
pop()
pospos+1
Return A[pos]
end pop
Which of the following will initialize an empty stack with capacity N for the above implementation?
operations are defined by the following code.
push(x)
A[pos] x
pos pos+1
end push
pop()
pospos+1
Return A[pos]
end pop
Which of the following will initialize an empty stack with capacity N for the above implementation?
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pos ← -1
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pos ← 0
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pos ← 1
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pos ←N-1
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Question 17 Explanation:
If you check push function, for every push we are decrementing pos by one.
Now if you imagine an array of length N-1, for every push the empty indices are getting decremented.
To explain in detail,
consider an empty array, so number of empty indices are N-1 ……(1)
When we push one element into it, the empty indices will reduce by 1 (i.e. decreented.)
Hence, From equation 1 we can say that pos is initialised to N-1
Now if you imagine an array of length N-1, for every push the empty indices are getting decremented.
To explain in detail,
consider an empty array, so number of empty indices are N-1 ……(1)
When we push one element into it, the empty indices will reduce by 1 (i.e. decreented.)
Hence, From equation 1 we can say that pos is initialised to N-1
Correct Answer: D
Question 17 Explanation:
If you check push function, for every push we are decrementing pos by one.
Now if you imagine an array of length N-1, for every push the empty indices are getting decremented.
To explain in detail,
consider an empty array, so number of empty indices are N-1 ……(1)
When we push one element into it, the empty indices will reduce by 1 (i.e. decreented.)
Hence, From equation 1 we can say that pos is initialised to N-1
Now if you imagine an array of length N-1, for every push the empty indices are getting decremented.
To explain in detail,
consider an empty array, so number of empty indices are N-1 ……(1)
When we push one element into it, the empty indices will reduce by 1 (i.e. decreented.)
Hence, From equation 1 we can say that pos is initialised to N-1