foo.cc: In function 'void dij()':
foo.cc:61:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<v[t].size();i++)
               ~^~~~~~~~~~~~
foo.cc:55:7: warning: unused variable 'abc' [-Wunused-variable]
  }int abc=0;
       ^~~

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