Skip to content

Latest commit

 

History

History
52 lines (43 loc) · 2.37 KB

README.md

File metadata and controls

52 lines (43 loc) · 2.37 KB

Implement a queue using two stacks

A queue is a collection which takes the value being inserted and puts it at the end of the collection (or line). The queue works using a first in first out (FIFO) order. A stack is a collection which takes the value being inserted and puts it at the top of the collection. The stack works using a last in first out (LIFO) order which is the opposite of a queue. For this code kata we are going to implement a queue using two stacks.

###TASK Implement the following methods for your queue class (FIFO):

  • void Enqueue(int value) - this method adds the value to the front of the queue.
  • int Dequeue() - this method will get the value from the front of the queue and remove it from the list.
  • Note: Use two stacks to implement the internals of the queue.

Implement the following methods for your stack class (LIFO):

  • void Push(int value) - this method adds the value to the top of the stack.
  • int Pop() - this method gets the value from the top of the stack and removes it from the list.

Use whatever programming language you prefer to solve this problem.

###INPUT Use the following items as example inputs:

  • queue.Enqueue(1);
  • queue.Enqueue(2);
  • queue.Enqueue(3);
  • queue.Dequeue();
  • queue.Enqueue(4);
  • queue.Enqueue(5);
  • queue.Dequeue();
  • queue.Dequeue();
  • queue.Dequeue();
  • queue.Dequeue();

###OUTPUT These are the outputs you should expect from the above inputs:

  • queue = { 1 }
  • queue = { 1, 2 }
  • queue = { 1, 2, 3 }
  • Dequeue method returns 1, queue = { 2, 3 }
  • queue = { 2, 3, 4 }
  • queue = { 2, 3, 4, 5 }
  • Dequeue method returns 2, queue = { 3, 4, 5}
  • Dequeue method returns 3, queue = { 4, 5 }
  • Dequeue method returns 4, queue = { 5 }
  • Dequeue method returns 5, queue = { }

####REFERENCE David Hudson and I were discussing this very problem over lunch last week. He even mentioned that it would be a good code kata and I agreed 100% which is how this code kata was formulated. Thanks, David!

Answer Submission Instructions

  1. Fork this repository.
  2. Write your solution to the problem.
  3. Commit your solution to your forked repository.
  4. Post a link to your fork as a comment to the Queue using two stacks post.