/in/foo.cc: In function 'int main()':
/in/foo.cc:60:5: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(b);
     ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/c++/6/ext/string_conversions.h:43,
                 from /usr/include/c++/6/bits/basic_string.h:5417,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bitset:47,
                 from /in/foo.cc:5:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:60:11: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(b);
           ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/c++/6/ext/string_conversions.h:43,
                 from /usr/include/c++/6/bits/basic_string.h:5417,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bitset:47,
                 from /in/foo.cc:5:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:61:5: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(a);
     ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/c++/6/ext/string_conversions.h:43,
                 from /usr/include/c++/6/bits/basic_string.h:5417,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bitset:47,
                 from /in/foo.cc:5:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:61:11: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(a);
           ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/c++/6/ext/string_conversions.h:43,
                 from /usr/include/c++/6/bits/basic_string.h:5417,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bitset:47,
                 from /in/foo.cc:5:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:69:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0;i<strlen(b);i++)
                  ~^~~~~~~~~~
/in/foo.cc:73:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0;i+strlen(b)<aa;i++)
                  ~~~~~~~~~~~^~~
/in/foo.cc:75:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(!(i-1>=0&&a[i-1]==' '&&i+strlen(b)<aa&&a[i+bb]==' '))
                                   ~~~~~~~~~~~^~~
/tmp/ccD6pHg9.o: In function `main':
foo.cc:(.text.startup+0x16): warning: the `gets' function is dangerous and should not be used.