foo.cc: In function 'int main()':
foo.cc:23:8: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(c); 
        ^
In file included from /usr/include/c++/7/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:46,
                 from foo.cc:1:
/usr/include/stdio.h:638:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
foo.cc:23:6: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result [-Wunused-result]
  gets(c); 
  ~~~~^~~
/tmp/ccnrozkc.o: In function `main':
foo.cc:(.text.startup+0xa): warning: the `gets' function is dangerous and should not be used.

自豪的采用 HydroJudge 进行评测(github.com/hydro-dev/HydroJudge)

{"receive":"2020-07-10T03:55:07.696Z","handle":"2020-07-10T03:55:07.696Z","cache_start":"2020-07-10T03:55:07.718Z","read_cases":"2020-07-10T03:55:07.848Z","judge":"2020-07-10T03:55:07.851Z","done":"2020-07-10T03:55:10.190Z"}