The problem is in your check function, you are copying a (vector<char> v )and (vector<vector<int>> vis) every time you call check function. To avoid this make v and vis vector global.

The problem in this line:

bool check(int i,int j,vector<vector<char>> v,vector<vector<int>> vis)

Your vector<vector<char>> v and vector<vector<int>> vis are copied every time, when you call this function. Instead you should write somthing like: bool check(int i,int j,vector<vector<char>> &v,vector<vector<int>> &vis)

there is your AC solution with this fix 138716320

And write "\n" instead endl, because endl flushing output, what takes time (sorry for my bad english)