Mã chấm: 269804

Main.cc: In function ‘int main()’:
Main.cc:12:9: error: ‘a’ was not declared in this scope
         a[i] = c;
         ^
Main.cc:15:12: error: ‘a’ was not declared in this scope
         if(a[i]=='a' && a[i+1]=='?')
            ^
Main.cc:17:12: error: ‘a’ was not declared in this scope
         if(a[i]=='b' && a[i+1]=='?')
            ^
Main.cc:19:9: error: ‘a’ was not declared in this scope
      if(a[i]=='a' && a[i+1]=='a')
         ^
Main.cc:7:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     int n; scanf("%d", &n);
            ~~~~~^~~~~~~~~~
Main.cc:11:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%c", &c);
         ~~~~~^~~~~~~~~~