foo.cpp: In function 'void print(char*, char*)':
foo.cpp:5:20: error: 'strlen' was not declared in this scope
 if(strlen(backOrder)==0)
                    ^
foo.cpp:7:36: error: 'strlen' was not declared in this scope
 char c = backOrder[strlen(backOrder)-1];
                                    ^
foo.cpp:16:22: error: 'strcpy' was not declared in this scope
 strcpy(rmid,&midOrder);
                      ^