foo.cc: In function 'int main()':
foo.cc:39:9: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
   39 |     gets(s1);gets(s2);
      |     ~~~~^~~~
In file included from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/cstdio:42,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/ext/string_conversions.h:43,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/bits/basic_string.h:3960,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/string:53,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/bits/locale_classes.h:40,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/bits/ios_base.h:41,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/ios:42,
                 from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/ostream:38,
                 from iostream:39:
/nix/store/linb70pgp53f0kygxm5wk163dx22d681-glibc-2.37-45-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
foo.cc:39:18: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
   39 |     gets(s1);gets(s2);
      |              ~~~~^~~~
/nix/store/linb70pgp53f0kygxm5wk163dx22d681-glibc-2.37-45-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
/nix/store/3r87a2wq1w4l66wnsm7rqvy608mx23h6-binutils-2.40/bin/ld: /tmp/ccZaddnJ.o: in function `main':
foo.cc:(.text.startup+0x44): warning: the `gets' function is dangerous and should not be used.

[Hydro](https://hydro.ac)提供评测服务