Did not understand the logic of this problem. Kindly help.
Tiling Problem-2
Hey @Co-de.champ
Imagine you have a floor of size n × m and you are given tiles of size 1× m.
Now you can either place the tiles vertically. Where a tile can be either place vertically,meaning it will only occupy a cell of width 1 and a complete height of M
there are 3 possibilities:
n>m - here you can place a tile vertically(left with n-m,m) as well as horizontally(left with n-1,m).
n==m then there are always 2 ways - horizontally or vertically.
n<m here you have only 1 choice,that is to place tile horizontally, so 1 way only.
Also mere recursion won’t help in passing all test cases, you have to use DP.
Note: If u haven’t studied DP yet then skip this question for now.
what is the use of modulo in this ques?
Hey @Co-de.champ Answer can become very large such that not even long long can hold that
So that’s why its required in question itself that you return ans%10^9+7
Hint: Dont do modulo at last step only and do it in intermediate steps also by using this : (a+b)%m==(a%m+b%m)%m
Hey , If your doubt is resolved then please mark it resolved 
Otherwise let me know the issue .