String Problems

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

This track covers character counting, two-pointer scans, parsing, building and comparing strings, and simple stacks and hash maps on text. 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 Same Letters, New Order, Burrow Speak and Folder Depth.
• Core Problems: 16 medium problems such as Loudest Letters First, Biggest Joined Number and Next Clock Time.
• Hard Problems: 7 hard problems such as Is It a Number, Formula Atom Counter and Palindrome by Swaps.

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.