How to learn DSA effectively?

Question

I have recently started Dsa and I'm referring lectures. But I'm bit clueless. Regarding resources and all.
I have recently studied time complexity and NOTE DOWN important codes and their time complexity in my notebook. But I'm not sure from where i could practice questions and is it even necessary? Can I just complete DSA lectures first and afterwards solve LeetCode as a source of "practice". Or do I need to practice alternatively? If yes then what are the resources for DSA practice?
Sorry if it sounds stupid. I'm newbie in DSA

Answer 1

Manav Roy
You can try these sites, there are a lot of problems from easy to advance level:-

1. HackerRank - https://www.hackerrank.com/
2. LeetCode - https://leetcode.com/
3. Codeforces - https://codeforces.com/
4. CodeChef - https://www.codechef.com/
5. GeeksforGeeks - https://www.geeksforgeeks.org/
6. TopCoder - https://www.topcoder.com/
7. HackerEarth - https://www.hackerearth.com/

Answer 2

Are you sure that your lectures do not have any kind of labs or practice questions that go along with them?

If not, you can use the search feature on LeetCode or HackerRank to filter by the topic that the lecture is covering. Make sure you're noting to check they're beginner questions.

And don't forget the handiness of pseudocode when attempting to practice. You don't always have to jump straight into coding.