Regarding Tile Problem

I have tried using top down as well as bottom up approach of DP to do this problem, still getting run time error.

In this problem you have figured the base cases correct that if n<m then return 1 and if n==m return 2. The recurrsion relation will be that if n>m then add the two recursions . One with same function but n as n-1 and the other will be same function but with n= n-m . Now this will the two cases one in which tile are placed vertically will be where n=n-1 and the one where tiles are placed horizontally will be where n=n-m . And also i will recommend that rather than forming a recurrence relation try to take a array of size n+1 and fill it from index i= 1 where size of n =1 till index i= n and where each index has the total possible way of that case on that index i.