创建一个双向链表，并删除此双向链表中的数据项的示例程序，将以下代码保存到一个源文件中：remove_data_from_doubly_linked_list.c， 如下所示 –

#include #include struct node { int data; struct node *prev; struct node *next; }; struct node *head = NULL; struct node *last = NULL; struct node *current = NULL; //display the list void printList() { struct node *ptr = head; printf("n[head] <=>"); //start from the beginning while (ptr != NULL) { printf(" %d <=>", ptr->data); ptr = ptr->next; } printf(" [last]n"); } void print_backward() { struct node *ptr = last; printf("n[last] <=>"); //start from the beginning while (ptr != NULL) { printf(" %d <=>", ptr->data); ptr = ptr->prev; } printf(" [head]n"); } //Create Linked List void insert(int data) { // Allocate memory for new node; struct node *link = (struct node*) malloc(sizeof(struct node)); link->data = data; link->prev = NULL; link->next = NULL; // If head is empty, create new list if (head == NULL) { head = link; return; } current = head; // move to the end of the list while (current->next != NULL) current = current->next; // Insert link at the end of the list current->next = link; last = link; link->prev = current; } void remove_data(int data) { int pos = 0; struct node *pre_node; if (head == NULL) { printf("Linked List not initialized"); return; } if (head->data == data) { if (head->next != NULL) { head->next->prev = NULL; head = head->next; return; } else { head = NULL; printf("List is empty now"); return; } } else if (head->data != data && head->next == NULL) { printf("%d not found in the listn", data); return; } current = head; while (current->next != NULL && current->data != data) { pre_node = current; current = current->next; } if (current->data == data) { pre_node->next = pre_node->next->next; if (pre_node->next != NULL) { // link back pre_node->next->prev = pre_node; } else last = pre_node; free(current); } else printf("%d not found in the list.", data); } int main() { insert(10); insert(20); insert(30); insert(40); insert(50); insert(60); printList(); remove_data(20); remove_data(50); printList(); print_backward(); return 0; }

执行上面程序，得到以下结果 –

[head] <=> 10 <=> 20 <=> 30 <=> 40 <=> 50 <=> 60 <=> [last] [head] <=> 10 <=> 30 <=> 40 <=> 60 <=> [last] [last] <=> 60 <=> 40 <=> 30 <=> 10 <=> [head]

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