/in/foo.cc: In function 'void Delete(char*, int, int)':
/in/foo.cc:8:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (si >= 0 && si >= strlen(s) - 1) puts(s);
                    ~~~^~~~~~~~~~~~~~~~
/in/foo.cc:9:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (si >= 0 && si < strlen(s) - 1)
                    ~~~^~~~~~~~~~~~~~~
/in/foo.cc:14:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i = si; i < strlen(s); i++)
                      ~~^~~~~~~~~~~
/in/foo.cc:24:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i = si + len; i < strlen(s); i++)
                            ~~^~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:34:5: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(s);
     ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:34:11: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(s);
           ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/tmp/ccFQQSnR.o: In function `main':
foo.cc:(.text.startup+0xc): warning: the `gets' function is dangerous and should not be used.