---

Lỗi biên dịch:

Main.cc:17:13: warning: multi-character character constant [-Wmultichar]
             'aa'=0;
             ^~~~
Main.cc:24:12: warning: multi-character character constant [-Wmultichar]
            'ab'=1;
            ^~~~
Main.cc:31:14: warning: multi-character character constant [-Wmultichar]
              'bb'=0;
              ^~~~
Main.cc:36:13: warning: multi-character character constant [-Wmultichar]
             'ba'=-1;
             ^~~~
Main.cc: In function ‘int main()’:
Main.cc:9:11: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations]
     gets(s);
           ^
In file included from /usr/include/stdio.h:862:0,
                 from Main.cc:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:232:1: note: declared here
 gets (char *__str)
 ^~~~
Main.cc:13:17: warning: statement has no effect [-Wunused-value]
             s[i]=='a';
             ~~~~^~~~~
Main.cc:17:18: error: lvalue required as left operand of assignment
             'aa'=0;
                  ^
Main.cc:24:17: error: lvalue required as left operand of assignment
            'ab'=1;
                 ^
Main.cc:31:19: error: lvalue required as left operand of assignment
              'bb'=0;
                   ^
Main.cc:36:19: error: lvalue required as left operand of assignment
             'ba'=-1;
                   ^
Main.cc:9:9: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result]
     gets(s);
     ~~~~^~~