Discuss C++ Institute CPP Exam Topic 2 Question 77

Which are NOT valid instantiations of priority_queue object:

#include

using namespace std;

int main()

{

deque mydeck;list mylist; vector myvector;

priority_queue first;//line I

priority_queue > second;//line II

priority_queue third(first);//line III

priority_queue > fourth(third);//line IV

priority_queue > fifth(myvector.begin(), myvector.end());//line V

return 0;

}

Suggested Answer: E

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46 comments · newest first

Caprice 11 months ago

Definitely line IV, lists can't be used like that!

Carri 11 months ago

Wait, can you really use a list in a priority_queue?

Quentin 11 months ago

Line II is good too, deque works with priority_queue.

Tambra 11 months ago

I think line IV is the one that's not valid.

Brigette 11 months ago

Line III is valid, just a copy constructor.

Lettie 12 months ago

I practiced a similar question, and I think line V is fine because it uses a vector, which is a valid underlying container for a priority queue.

Avery 12 months ago

Line IV seems off to me; I don't recall if you can instantiate a priority queue with another priority queue as a parameter.

Carmelina 12 months ago

I remember something about the container types for priority queues, and I feel like line II is valid since deque is one of the allowed types.

Rosio 1 year ago

I think line III might be problematic because it looks like it's trying to copy a priority queue, but I'm not sure if that's allowed.

Erin 1 year ago

This looks like a tricky question, but I think I can figure it out. I'll need to carefully consider the valid container types for priority_queue and how they interact with the provided examples.

Bulah 1 year ago

I'm a bit confused by the different container types being used here. I'll need to refresh my memory on the requirements for the priority_queue constructor and make sure I understand the differences between these containers.

Christa 1 year ago

I think I know the answer to this one. The priority_queue container requires a specific type of underlying container, and not all of these options are valid. I'll need to double-check the details, but I'm feeling confident about this.

Alton 1 year ago

Okay, let me see. The first line seems straightforward, but the others might have some restrictions I'm not sure about. I'll have to review the priority_queue documentation to be sure.

Lashawna 1 year ago

Hmm, this looks tricky. I'll need to carefully read through the code and think about the requirements for a valid priority_queue instantiation.

Bong 1 year ago

This question seems straightforward, I'm pretty confident I can figure it out.

Winifred 1 year ago

I think the key here is to focus on the idea of consistency. Consistent service means treating all customers the same way, so the priority assignment should be based on a standardized agreement, not individual factors. I'm leaning towards option C, but I'll double-check the other choices just to be sure.

Zack 1 year ago

I'm torn between A and B because it could be tricky. Were there some conditions in the script that might lead to only nine objects being created instead?

Malcom 1 year ago

I'm pretty sure all the other lines are valid instantiations. Line IV is the only one that doesn't work. Now, if they asked me to instantiate a priority_queue with a banana, that would be a different story!

Shawnda 1 year ago

↳ replying to Malcom

I agree with you, line IV is the only one that doesn't work. The rest are valid instantiations.

Mary 1 year ago

↳ replying to Malcom

No, I'm pretty confident that line II is valid. It's line IV that doesn't work.

Stephaine 1 year ago

↳ replying to Malcom

Are you sure about that? I think line II is also not a valid instantiation.

Timothy 1 year ago

↳ replying to Malcom

E) line V

Antonio 1 year ago

↳ replying to Malcom

D) line IV

Raina 1 year ago

↳ replying to Malcom

C) line III

Margarita 1 year ago

↳ replying to Malcom

B) line II

Mattie 1 year ago

↳ replying to Malcom

A) line I

Cyril 1 year ago

Haha, it's funny how they try to trick us with a list. Who uses a list for a priority queue? That's like trying to use a toaster to dry your hair!

Eun 1 year ago

↳ replying to Cyril

It's like using a toaster to dry your hair, totally useless!

Lavonne 1 year ago

↳ replying to Cyril

C) line III

Paris 1 year ago

↳ replying to Cyril

I agree, a list is not efficient for a priority queue.

Irma 1 year ago

↳ replying to Cyril

Definitely! A priority queue should be implemented with a deque or a vector.

Buck 1 year ago

↳ replying to Cyril

Haha, I know right! Using a list for a priority queue is a bad idea.

Pamela 1 year ago

↳ replying to Cyril

B) line II

Lyda 1 year ago

↳ replying to Cyril

A) line I

Carissa 2 years ago

I believe line V is also not valid because it is trying to initialize a priority_queue with iterators from a vector.

Lauran 2 years ago

I agree with Van, line I is incorrect because it is missing the container type.

Van 2 years ago

I think line I is not a valid instantiation.

Maynard 2 years ago

I agree with Mabel. The list is not a valid container for a priority_queue, so line IV is not a valid instantiation.

Cecily 1 year ago

↳ replying to Maynard

That makes sense. Thanks for clarifying!

Sherrell 1 year ago

↳ replying to Maynard

So, the correct answer would be D) line IV.

Beckie 1 year ago

↳ replying to Maynard

Yes, I agree. The correct containers for priority_queue are deque and vector.

Marget 1 year ago

↳ replying to Maynard

I think line IV is not valid because list is not a valid container for priority_queue.

Carmela 2 years ago

I believe line V is also not valid because it is trying to initialize a priority_queue with iterators from a vector.

Darrin 2 years ago

I agree with Willetta, line I is incorrect because it is missing the container type.

Mabel 2 years ago

The correct answer is line IV. A priority_queue can only be instantiated with a deque or a vector as the underlying container, not a list.

Willetta 2 years ago

I think line I is not a valid instantiation.

C++ Institute CPP Exam - Topic 2 Question 77 Discussion