I am solving codeforces problems. Now I am trying to solve a problem but again and again I am failing. It is almost 3 days I am working on this problem, figuring out different ideas but every times I am getting failed. I am also doing a lot of sketch but not getting an appropriate algo. Basically, what algo needs for that algo I already know, have seen tag. I have a option to look on other solution/tutorial. But I never feel comfort on this job. I want to know, is it unnecessary to spend too much times for a particular problem although I am figuring out different inefficient solution. What should I do now?