In the standard linked-list representation of a stack, where TOP points to the…
2017
In the standard linked-list representation of a stack, where TOP points to the first node and links continue toward older stack elements, the null pointer of the last node in the list represents:
- A.
Beginning of the stack
- B.
Bottom of the stack
- C.
Middle of the stack
- D.
In between some value
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Correct answer: B
Correct answer: Bottom of the stack.
Standard assumption: In a linked stack, insertion and deletion are normally performed at the TOP/front node so push and pop remain O(1).
Link direction: Each node points to the next older element in the stack.
Null pointer: The last node has no older element below it, so its link is NULL. That NULL link marks the bottom of the stack, not the top.