Help with approach

#1

prob: https://hack.codingblocks.com/app/contests/2022/455/problem

In this question just about making a queue using 2 stacks?

#2

Dequeue efficient. makes sure that oldest entered element is always at the top of stack 1, so that deQueue operation just pops from stack1. To put the element at top of stack1, stack2 is used.

enQueue(q, x):

  • While stack1 is not empty, push everything from stack1 to stack2.
  • Push x to stack1 (assuming size of stacks is unlimited).
  • Push everything back to stack1.

Here time complexity will be O(n)

deQueue(q):

  • If stack1 is empty then error
  • Pop an item from stack1 and return it

Here time complexity will be O(1)

now try to write code
if find difficulty feel free to ask