/in/foo.cc: In member function 'void Solution::search(int, int, std::vector<std::vector<int> >&, std::vector<std::vector<char> >&)':
/in/foo.cc:11:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         while(i<grid.size()&&j<grid[i].size()&&i>=0&&j>=0)
               ~^~~~~~~~~~~~
/in/foo.cc:11:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         while(i<grid.size()&&j<grid[i].size()&&i>=0&&j>=0)
                              ~^~~~~~~~~~~~~~~
/in/foo.cc: In member function 'int Solution::numIslands(std::vector<std::vector<char> >&)':
/in/foo.cc:29:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<grid.size();i++)
                     ~^~~~~~~~~~~~
/in/foo.cc:32:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for(int j=0;j<grid[i].size();j++)
                         ~^~~~~~~~~~~~~~~
/in/foo.cc:43:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         while(i<x.size()){
               ~^~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:57:32: error: invalid declarator before 'T'
  int n, m, vector<vector<int>> T;
                                ^
/in/foo.cc:59:7: error: 'T' was not declared in this scope
  cin>>T
       ^
/in/foo.cc:70:9: error: 'numIslands' was not declared in this scope
  return numIslands(T);
         ^~~~~~~~~~