Stack and Queue Problems

Practise 35 stack and queue problems from basics to advanced in Python, C++, Java, JavaScript and TypeScript.

This track covers bracket matching, expression evaluation, monotonic stacks and queues, queues built from stacks, and sliding window maximums. The problems run from easy to hard, so each idea builds on the one before. Every problem is judged against hidden test cases in five languages.

What you will practise:

• Basics: 12 easy problems such as Bracket Balance, Folder Depth and Streak Watcher.
• Core Problems: 16 medium problems such as Tidy the Path, Possible Stack Order and Zigzag Feed.
• Hard Problems: 7 hard problems such as Window Peaks, Truth Expression and Odd-Even Leaps.

Start with the basics, move on to the core problems, and try the hard ones when the pattern feels natural. Every problem comes with worked examples and clear constraints. For a full path across all of DSA, see Revquix 80, Revquix 150 and Revquix 300.