Ad:

C++ Discussion Thread
Unsolved
Views: 555

Oct 5th, 2009

Help with Queues and Stacks please

Expand Post »

Hey guys.

I need help with these questions please

1. Write a function that takes as a parameter a queue of integers and returns a copy of the queue with all the elements stored in reverse order. Use a stack as a helper data structure.

C++ Syntax (Toggle Plain Text)
queue<int> reverseQueue(queue<int> q)
// pre: none
// post: returns a queue with the elements stored in reverse order
queue<int> reverseQueue(queue<int> q)
// pre: none
// post: returns a queue with the elements stored in reverse order

For example, after creating a queue in the following way and calling the function:

C++ Syntax (Toggle Plain Text)
 queue<int> myQueue, rQueue;
      myQueue.push(1);
      myQueue.push(2);
      myQueue.push(3);
      rQueue = reverseQueue(myQueue);
 queue<int> myQueue, rQueue;
      myQueue.push(1);
      myQueue.push(2);
      myQueue.push(3);
      rQueue = reverseQueue(myQueue);

then the resulting rQueue has 1 at the back, 2 in the middle, and 3 at the front.

2. Write a function that reverses a string by making use of a stack. Your function could push elements on the stack one by one, and then build up the result by popping them off the stack.

C++ Syntax (Toggle Plain Text)

 string reverseString(string s)

Any help would be appreciated.

Thanks

Similar Threads

Sudoku Mini grid help! in C++
how to allocate x number of queues? in C++
java projects in Java
How did you learn C++? in C++
Stacks and Queues in C++

scantraXx-

Reputation Points: 1

Solved Threads: 0

Light Poster

Offline

27 posts
since Aug 2009

Permalink

Oct 5th, 2009

Re: Help with Queues and Stacks please

prob 1.

Remove all the elements of the queue and push it in the stack.
Now pop from the stack one element at a time and add it to the new queue until the stack is empty. Now return the new queue.

prob 2.

the answer is there in your question itself. Just do as its said.

***IMP : Dont expect readymade code in here.
If u want them then u r in the wrong place.

dkalita

Reputation Points: 121

Solved Threads: 61

Posting Pro in Training

Offline

402 posts
since Sep 2009

Permalink

Oct 5th, 2009

Re: Help with Queues and Stacks please

Click to Expand / Collapse Quote originally posted by scantraXx- ...

2. Write a function that reverses a string by making use of a stack. Your function could push elements on the stack one by one, and then build up the result by popping them off the stack.

Use the push function to add each element of the string onto the stack, then use the pop function to remove each element. You can print each value after popping, then move onto the next element until the stack is empty.

Grn Xtrm

Reputation Points: 100

Solved Threads: 48

Posting Pro in Training

Offline

495 posts
since Nov 2008

Permalink

Oct 6th, 2009

Re: Help with Queues and Stacks please

Draw these out and trace through the algorithm and it will make much more sense.

chunalt787

Reputation Points: 39

Solved Threads: 1

Junior Poster in Training

Offline

84 posts
since Apr 2008

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

Previous Thread in C++ Forum Timeline: Reading an outside file mortgage calculator

Next Thread in C++ Forum Timeline: Family Age Statistics Program

DaniWeb Message

Cancel Changes

User Name
Password