foo.cc: In function 'int main(int, char**)':
foo.cc:4:7: error: expected ';' before ')' token
  for(n):
       ^
foo.cc:5:19: warning: statement has no effect [-Wunused-value]
         scanf(b,c);
                   ^
foo.cc:6:14: error: invalid conversion from 'int' to 'const char*' [-fpermissive]
      printf(b*c);
             ~^~
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/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from foo.cc:1:
/usr/include/stdio.h:364:12: note:   initializing argument 1 of 'int printf(const char*, ...)'
 extern int printf (const char *__restrict __format, ...);
            ^~~~~~
foo.cc:7:2: error: expected primary-expression before 'return'
  return 0;
  ^~~~~~
foo.cc:7:2: error: expected ')' before 'return'

自豪的采用jd5进行评测(github.com/masnn/jd5)