48     node* tmp;  variable
52     Map() : head( NULL ), tail ( NULL ),tmp(head),size_of_list(0) {}  in Map()
79     tmp = head;  in find()
80     while(tmp)  in find()
82         if(tmp->data == d1)  in find()
84             return tmp->data2;  in find()
86         tmp = tmp->next;  in find()
94     tmp = head;  in find_ele()
95     while(tmp)  in find_ele()
97         if(tmp->data == d1)  in find_ele()
99             return tmp->data;  in find_ele()
101         tmp = tmp->next;  in find_ele()
109     tmp = head;  in begin()
110     if(tmp)  in begin()
112         return (tmp->data2);  in begin()
120     tmp = head;  in show()
121     while(tmp)  in show()
123         printf("%d-->%d\n",tmp->data,tmp->data2);  in show()
124         tmp = tmp->next;  in show()
132     tmp = head;  in size()
133     while(tmp)  in size()
135         tmp = tmp->next;  in size()
151         tmp=head;  in insert()
153     tmp = head;  in insert()
161     tmp = head;  in erase()
162     node* prevnode = tmp;  in erase()
165     while(tmp)  in erase()
175         if((tmp ==head) && (tmp->data ==d))  in erase()
178             tempnode = tmp;  in erase()
179             tmp = tmp->next;  in erase()
180             tmp->prev = NULL;  in erase()
181             head = tmp;  in erase()
186         if((tmp == tail) && (tmp->data ==d))  in erase()
189             tempnode = tmp;  in erase()
191             tmp->prev = NULL;  in erase()
196         if(tmp->data == d)  in erase()
199             prevnode->next = tmp->next;  in erase()
200             tmp->next->prev = prevnode->next;  in erase()
201             tempnode = tmp;  in erase()
206         prevnode = tmp;  in erase()
207         tmp = tmp->next;  in erase()
217     tmp = head;  in eraseall()