I went through, for example, the binary search section, learned it, and did most of the practice problems ( some were on my own, some not, and some were hard …)
I have two options:
1- do more additional problems from any other judge on this topic TILL I feel comfortable ( no time limit? ).
2- move on to the next topic / section and cover more topics and the practice problems were enough for NOW.
which should I follow ?
In general, I think it’s useful to get a wider exposure to topics than to spend time mastering one. Obviously the end goal is to get mastery in all topics, but by doing a wide range of topics, they will improve your general problem solving, so, when you return to your weaker topics, you might find them easier.
Also, while doing other topics, since binary search is a frequently used algorithm, you’re likely to get more practice using it.