/in/foo.cc: In function 'int spfa(int, int, long long int&, long long int&)':
/in/foo.cc:37:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<g[u].size();++i) {
                ~^~~~~~~~~~~~
/in/foo.cc:28:31: warning: iteration 1005 invokes undefined behavior [-Waggressive-loop-optimizations]
  for(int i=0;i<=1005;++i) d[i]=INF;
                           ~~~~^~~~
/in/foo.cc:28:15: note: within this loop
  for(int i=0;i<=1005;++i) d[i]=INF;
              ~^~~~~~