foo.cc: In function 'void dfs(std::string)':
foo.cc:8:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |  for (int i=0;i<now.length();i++)
      |               ~^~~~~~~~~~~~~
foo.cc:11:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |   for (int j=0;j<now.length();j++)
      |                ~^~~~~~~~~~~~~
foo.cc:19:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |    for (int j=0;j<now.length();j++)
      |                 ~^~~~~~~~~~~~~
foo.cc:37:18: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   37 |   if(now.length()>maxs)
      |      ~~~~~~~~~~~~^~~~~
foo.cc: In function 'int main()':
foo.cc:50:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   50 |   freopen("109.txt","r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
foo.cc:56:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   56 |    freopen("109.txt","w",stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
foo.cc:63:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   63 |    freopen("109.txt","w",stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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