My logic is giving WA on 50% of the test cases. I am not able to figure out what is wrong with my logic. Any help would be great.

Logic: I apply a regular dfs, and return true or false. True indicates, that it is indeed the shortest the path, while false indicates, that it is not. If we get a true, then we update the parent node, else we don't.

Code: Code

UPDATE: Solved using DP but would be curious to know, if anyone can do it without DP.