foo.cc: In function 'void dts::tr_dfs1(int, int)':
foo.cc:28:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |         for (int i=0;i<tr[now].s.size();i++)
      |                      ~^~~~~~~~~~~~~~~~~
foo.cc: In function 'void dts::tr_dfs2(int, int)':
foo.cc:48:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |             for (int i=0;i<tr[now].s.size();i++)
      |                          ~^~~~~~~~~~~~~~~~~
foo.cc: In function 'void dts::main()':
foo.cc:208:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  208 |         scanf("%d",&n);
      |         ~~~~~^~~~~~~~~
foo.cc:210:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  210 |             scanf("%d",&data[i]);
      |             ~~~~~^~~~~~~~~~~~~~~
foo.cc:216:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  216 |             scanf("%d%d",&x,&y);
      |             ~~~~~^~~~~~~~~~~~~~
foo.cc:223:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  223 |         scanf("%d",&m);
      |         ~~~~~^~~~~~~~~
foo.cc:227:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  227 |             scanf("%d%d%d",&K,&x,&y);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:233:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  233 |                 scanf("%d",&val);
      |                 ~~~~~^~~~~~~~~~~

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