How can I learn data structures and algorithms deeply instead of just grinding problems?

A formal college-level data structures and algorithms course is one possible route. Whether you take a class or study independently, look for material that covers arrays, linked lists, stacks, queues, trees, graphs, hashing, sorting, searching, recursion, dynamic programming, and complexity analysis. Once those basics feel comfortable, competitive programming will be easier to approach.

Focus on understanding the purpose and structure of each data structure rather than memorizing solutions. For example, when studying trees, implement your own tree, learn different traversal methods such as breadth-first and depth-first search, and explore practical uses like expression parsing or spatial indexing. The point of a DSA course is to recognize the shape of a problem, choose an appropriate data structure, and understand which algorithms work with it. Use problems as opportunities to apply those ideas, not as a list of solutions to memorize.

A structured course or textbook can give you a solid sequence for learning the fundamentals. Practice implementing the structures and algorithms yourself, analyze their time and space complexity, and then solve progressively harder problems to reinforce each topic. Problem-solving platforms can be useful for practice, but they work best after you understand the underlying concepts rather than as your main source of instruction.