/in/foo.cc: In function 'int visit(int, int, int)':
/in/foo.cc:22:5: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
     else
     ^~~~
/in/foo.cc:24:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else'
   for(int i=0;i<ve[begin].size();i++)
   ^~~
/in/foo.cc:24:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<ve[begin].size();i++)
               ~^~~~~~~~~~~~~~~~~
/in/foo.cc: At global scope:
/in/foo.cc:39:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^