foo.cc: In function 'void dts::dfs(std::vector<long long int>)':
foo.cc:24:26: warning: comparison of integer expressions of different signedness: 'dts::ll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |             for (ll i=0;i<rec.size();i++)
      |                         ~^~~~~~~~~~~
foo.cc:25:32: warning: comparison of integer expressions of different signedness: 'dts::ll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |                 for (ll j=i+1;j<rec.size();j++)
      |                               ~^~~~~~~~~~~
foo.cc:27:38: warning: comparison of integer expressions of different signedness: 'dts::ll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |                     for (ll k=0,l=0;k<rec.size();k++)
      |                                     ~^~~~~~~~~~~

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