Tilling Problem------------------------

#1

Here is the code that i wrote , i have used recursion with memoization to solve this problem but im getting only one test case correct.
I’m not getting what mistake i am making.
Please point out my mistake

#2

@neil_gautam you are not using the memo array correctly.

  1. Its size should be n+1 so you can access memo[n]
  2. In the recursive case before you make a recursive call, check if answer exists in memo array or not, if it does then you dont need to make the recursive call.
if (memo[n] != 0) {
     return memo[n];
 }
#3

@neil_gautam
also

 return  memo[n-1]+memo[n-m];

is not correct,

you should take modulo each time with 10^9 +7 (as given in the question) and update your memo[n] if you have to calculate it using recursion…
See below;

Correction required :
return memo[n]=(memo[n-1]+memo[n-m])%mod;
where mod=10^9 +7

#4

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