foo.cpp: In function 'void clean(block*)':
foo.cpp:17:34: error: 'memset' was not declared in this scope
     memset(op->em,0,sizeof op->em);
                                  ^
foo.cpp: In function 'void Remove(block*, int, int)':
foo.cpp:134:6: warning: unused variable 'ttt' [-Wunused-variable]
  int ttt=num;
      ^