Hi all, I am kind of confused i have solved some problems(more than 100) in leetcode but still i feel noob.

I am not able to solve most of the random questions from random assessments.Sometimes i stuck in that how to start? where to start ? What will help me here?

For example i was solving longest pandiromic substring in assessment. I did not solve it before and i never thought that i can use DP here.This is just one example.I always get demotivated because of this. How can i improve this?

Also my concepts 'remembering and understanding technique' is also very very poor. I solve question and forget about it. I never make notes. I feel that there are many articles and books is are already present so i dont need it. Am i doing something wrong here?

Please suggest me the best techniques, ways and all little but important things that help me to achieve this.

(Sorry for poor English)

Thanks