There are many famous topics such as Dp, graph theory, Combinatrics.

We know different algorithms and approach such as bitmask DP technique , memorization technique, iteration technique.

Or in graph theory we know BFS, DFS< Dijkstra , MST, Eular trail/circuit and many more.

As a beginner I have learned those famous techniques and many variation by solving problems on different oj.

But now I see that a difficult problem have been appeared , though I have learned this topics I fail many times to solve their variation .

Those variation are always untold or not seen on blogs . But it is hard for me to solve those variation by my own as I am a beginner.

Such as I have learned Eular trail/circuit, I have solved several problems and I thought I could be able to solve any problem related to eular trail/circuit .

But then I stuck on a problem and couldn't solve it , I tried it many hours . Then I searched for solution and seen that , this problem was chinese postman problem . Then I learned about chinese postman and solved this.

Same way I learned tiling DP .

Now I think I should know about those topics which are always untold.

Please tell me as much topics as you can , please give me the link if you can .

Or at least tell as much topics as you can.

I think this will help beginners like me.