foo.cc: In function 'int main()':
foo.cc:8:8: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(s);
        ^
In file included from /usr/include/stdio.h:862:0,
                 from /usr/include/c++/7/cstdio:42,
                 from /usr/include/c++/7/ext/string_conversions.h:43,
                 from /usr/include/c++/7/bits/basic_string.h:6361,
                 from /usr/include/c++/7/string:52,
                 from /usr/include/c++/7/bits/locale_classes.h:40,
                 from /usr/include/c++/7/bits/ios_base.h:41,
                 from /usr/include/c++/7/ios:42,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from foo.cc:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:232:1: note: declared here
 gets (char *__str)
 ^~~~
foo.cc:9:6: warning: unused variable 'min' [-Wunused-variable]
  int min=findmin(s);
      ^~~
foo.cc:8:6: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result [-Wunused-result]
  gets(s);
  ~~~~^~~
foo.cc: In function 'int findmin(char*)':
foo.cc:32:20: warning: 'tmp' may be used uninitialized in this function [-Wmaybe-uninitialized]
   for(int i=tmp;s[i]!=0;i++)
                    ^
/tmp/cc3XV2ql.o: In function `main':
foo.cc:(.text.startup+0x2c): warning: the `gets' function is dangerous and should not be used.

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