Implement a fixed-size queue data structure that stores integers. The queue should have a maximum size and support enqueue and dequeue operations. Return -1 when trying to dequeue from an empty queue or enqueue to a full queue.

Examples:

Input: operations = [ 'enqueue 1', // returns 1 'enqueue 2', // returns 2 'enqueue 3', // returns -1 (queue is full, size=2) 'dequeue', // returns 1 'enqueue 3', // returns 3 'dequeue' // returns 2 ] maxSize = 2 Output: [1, 2, -1, 1, 3, 2] Explanation: Queue operations with max size 2, showing return values for each operation Input: operations = [ 'dequeue', // returns -1 (empty queue) 'enqueue 1', // returns 1 'dequeue' // returns 1 ] maxSize = 1 Output: [-1, 1, 1] Explanation: Queue operations with max size 1, starting with dequeue on empty queue

Method used to process your code

public static List<Integer> processQueueOperations(List<String> operations, Integer maxSize) { FixedSizeQueue queue = new FixedSizeQueue(maxSize); List<Integer> results = new List<Integer>(); for (String operation : operations) { if (operation.startsWith('enqueue')) { Integer item = Integer.valueOf(operation.split(' ')[1]); results.add(queue.enqueue(item)); } else if (operation == 'dequeue') { results.add(queue.dequeue()); } } return results; }
Apex Code Editor
Log In
Log in to submit your code and save your progress.

Welcome to Lightning Challenge!

Create an Account

Sign up to track your progress, earn points, and compete with others. Your solutions will be saved automatically.

Create account

How It Works

  • • Write your solution in the code editor
  • • Connect your Salesforce org to test
  • • Submit to check if your solution passes
  • • Use hints if you get stuck

Contest Alert

🏆 #CodeEveryDay Contest

Two ways to win a free Salesforce certification voucher:

  • The #1 ranked player on our #CodeEveryDay leaderboard by June 28th
  • Complete challenges to enter our random drawing! Each challenge you complete gives you an additional entry, increasing your chances to win.

Contest runs June 16-28. Additional prizes available for other top leaderboard positions. Track your position and compete for prizes!

Points are only calculated for questions created and completed during the contest period. If you previously won, you are not eligible to win the certification voucher again.