I often struggle with such problems which require some minute observation i.e. mainly problems with some sort of constructive approach or those which are based on game theory(without any rigourous maths). Either i am not able to find any sort of pattern or it takes me too much of time to do so. Can anyone share their approach towards such problems or some practise method that helped them to gain an edge over such problems?
We all struggle with that... Just solve more problems and you'll start to improve at them.
Thanks for the advice.
In the Questions containing observations I usually try to deduce the answer by looking at the sample test cases as fast as possible
This might help: How to get started with solving Ad-Hoc tasks on codeforces