foo.cc: In function 'void bfs()':
foo.cc:20:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |                 for (int i = 0; i < g[u].size(); ++i) {
      |                                 ~~^~~~~~~~~~~~~

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Found 10 testcases.
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