/in/foo.cc: In function 'int main()':
/in/foo.cc:12:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      for(int i=0;i<s[n].size();i++)
                  ~^~~~~~~~~~~~
/in/foo.cc:20:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0;j<s[i].size();j++){
                     ~^~~~~~~~~~~~
/in/foo.cc:22:17: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
                 for(int k=1;k<=tc1;k++)cout<<a[k]<<':'<<b[k]<<endl;cout<<endl;
                 ^~~
/in/foo.cc:22:68: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
                 for(int k=1;k<=tc1;k++)cout<<a[k]<<':'<<b[k]<<endl;cout<<endl;
                                                                    ^~~~