二十五岁时我们都一样愚蠢、多愁善感，喜欢故弄玄虚，可如果不那样的话，五十岁时也就不会如此明智。
标题：C示例从双向链接列表中删除数据
C示例从双向链接列表中删除数据
#include <stdio.h> #include <stdlib.h> 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 list\n", 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(1); insert(40); insert(56); printList(); remove_data(20); printList(); print_backward(); return 0; }
