InterviewBit Problems   Distinct Subsequences : Unsolved

About the Distinct Subsequences : Unsolved category (1)
Don't waste your valuable time here (3)
To prevent TLE, space complexity should be O(m) and time complexity should be O(n*m). Also add pre-check condition if len(A)<len(B): return 0 (2)
No need of DP. Recursion without DP accepted (really) (1)
O(M * N) Top Down DP solution giving TLE (2)
Nice one.Took me 35 minutes (3)
Bottom up approach works (1)
With O(N) space, and in len(t)*len(s) (1)
Deleted the comment (1)
Python Solution gives wrong answer (1)
Tle for m*n solution how this is possible (2)
Why is my solution giving incorrect answers? Please help (3)
Geeting wrong answer on interviewbit but correct answer on other online judges like hackerrank, codeforces etc (1)