/in/foo.cc: In function 'void bb(int)':
/in/foo.cc:31:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<l[xi].size();i++){
              ~^~~~~~~~~~~~~
/in/foo.cc: In function 'void wg(int, int)':
/in/foo.cc:48:6: warning: unused variable 'j' [-Wunused-variable]
  int j=0;
      ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:75:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<b.size();i++)
              ~^~~~~~~~~
/in/foo.cc: In function 'void wg(int, int)':
/in/foo.cc:42:6: warning: 'mi' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int mi;
      ^~