Challenge Summary

This challenge asks us to implement a PseudoQueue using 2 Stacks in order to enqueue and dequeue successfully to the queue within FIFO approach.

Whiteboard Process

Approach & Efficiency

For my code I used stack1 to save the data in general and stack2 to reverse the data in when needed. My approach’s time and memory complexity goes as follows:

• enqueue : time O(1), memory O(1) since we only push an element to stack1.
• dequeue : time O(n), memory O(n) since we loop over stack1 to reverse it in stack2 to pop the last(becomes the first) element and then reverse it back to stack1.
• toString : time O(n), memory O(n) since we make a copy of stack1 and reverse that copy in stack2 to print it in the correct order.

  Solution

  To run my code you can use :

• To initialize a new PseudoQueue :
  PseudoQueue<variableType> pQname = new PseudoQueue<variableType>();
• To enqueue a new value :
  pQname.enqueue(newValue);
• To dequeue a value from the PseudoQueue :
  pQname.dequeue();
• and you can save the enqueued value into a variable.