foo.cc: In function 'void dts::dfs(std::vector<double>)':
foo.cc:35:26: warning: comparison of integer expressions of different signedness: 'dts::ll' {aka 'long long int'} and 'std::vector<double>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |             for (ll i=0;i<rec.size();i++)
      |                         ~^~~~~~~~~~~
foo.cc:36:32: warning: comparison of integer expressions of different signedness: 'dts::ll' {aka 'long long int'} and 'std::vector<double>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |                 for (ll j=i+1;j<rec.size();j++)
      |                               ~^~~~~~~~~~~
foo.cc:38:38: warning: comparison of integer expressions of different signedness: 'dts::ll' {aka 'long long int'} and 'std::vector<double>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |                     for (ll k=0,l=0;k<rec.size();k++)
      |                                     ~^~~~~~~~~~~
foo.cc: In function 'void dts::main()':
foo.cc:69:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   69 |             scanf("%lf",&a[i]);
      |             ~~~~~^~~~~~~~~~~~~
foo.cc:73:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   73 |                 scanf("%lf",&key);
      |                 ~~~~~^~~~~~~~~~~~

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