/in/foo.cc: In function 'void spfa(int)':
/in/foo.cc:50:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<mymap[now.mynext].size();i++)
               ~^~~~~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:91:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<=in.size();j++)
               ~^~~~~~~~~~~
/in/foo.cc:94:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(in[j]!=' '&&j<in.size()) k=k*10+in[j]-'0';
                   ~^~~~~~~~~~