/in/foo.cc: In member function 'str str::operator+(const str&) const':
/in/foo.cc:32:40: error: 'memset' was not declared in this scope
            memset(c.num,0,sizeof(c.num));
                                        ^
/in/foo.cc:37:70: error: 'memcpy' was not declared in this scope
               memcpy(&c.num[j+1],&a.num[j+1],(a.num[0]-j)*sizeof(int));
                                                                      ^
/in/foo.cc:40:70: error: 'memcpy' was not declared in this scope
               memcpy(&c.num[j+1],&b.num[j+1],(b.num[0]-j)*sizeof(int));
                                                                      ^
/in/foo.cc: In member function 'str str::operator*(const int&) const':
/in/foo.cc:57:40: error: 'memset' was not declared in this scope
            memset(c.num,0,sizeof(c.num));
                                        ^