foo.cc: In function 'void dfs(int, int)':
foo.cc:15:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |  for(int i=0;i<a[u].size();i++)
      |              ~^~~~~~~~~~~~
foo.cc: In function 'int dfs2(int, int)':
foo.cc:33:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |  for(int i=0;i<a[u].size();i++)
      |              ~^~~~~~~~~~~~

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Found 5 testcases.
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