FazeelUsmani / Amazon-SDE-Preparation

This repository includes all the interview preparation questions for Amazon SDE role
https://practice.geeksforgeeks.org/batch/Amazon-Test-Series
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08 Stack --> 04 Stack using two queues #89

Open FazeelUsmani opened 3 years ago

FazeelUsmani commented 3 years ago
  1. Stack using two queues

Implement a Stack using two queues q1 and q2.

Example 1: Input: push(2) push(3) pop() push(4) pop() Output: 3 4 Explanation: push(2) the stack will be {2} push(3) the stack will be {2 3} pop() poped element will be 3 the stack will be {2} push(4) the stack will be {2 4} pop() poped element will be 4
Example 2:

Input: push(2) pop() pop() push(3) Output: 2 -1 Your Task:

Since this is a function problem, you don't need to take inputs. You are required to complete the two methods push() which takes an integer 'x' as input denoting the element to be pushed into the stack and pop() which returns the integer poped out from the stack(-1 if the stack is empty).

Expected Time Complexity: O(1) for push() and O(N) for pop() (or vice-versa). Expected Auxiliary Space: O(1) for both push() and pop().

Constraints: 1 <= Number of queries <= 100 1 <= values of the stack <= 100

Shubham0599 commented 2 years ago

Hello ! can you assign this to me Looking forward to contribute