foo.cc: In function 'bool bellmanford()':
foo.cc:31:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |             for (int k=0;k<g[j].size();k++) {
      |                          ~^~~~~~~~~~~~

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