C语言双向链表快速入门教程

链表的声明

double_linked_list.h

#ifndef ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H
#define ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

// 双向链表的节点
typedef struct doubleLinkedListNode {
    int data;
    struct doubleLinkedListNode *next; // 下一个节点
    struct doubleLinkedListNode *prev; // 上一个节点
} DoubleLinkedListNode;

// 双向链表
typedef struct doubleLinkedList {
    DoubleLinkedListNode *head; // 头节点
    DoubleLinkedListNode *tail; // 尾节点
} DoubleLinkedList;

#endif //ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

创建双向链表

double_linked_list.h

#ifndef ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H
#define ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

// 双向链表的节点
typedef struct doubleLinkedListNode {
    int data;
    struct doubleLinkedListNode *next; // 下一个节点
    struct doubleLinkedListNode *prev; // 上一个节点
} DoubleLinkedListNode;

// 双向链表
typedef struct doubleLinkedList {
    DoubleLinkedListNode head; // 头节点
    DoubleLinkedListNode tail; // 尾节点
} DoubleLinkedList;

#endif //ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

double_linked_list.c

#include "double_linked_list.h"

// 创建头节点
DoubleLinkedListNode *_newDoubleLinkedListNode(int value) {
    // 申请节点的空间
    DoubleLinkedListNode *node = malloc(sizeof(DoubleLinkedListNode));

    // 初始化
    node->next = NULL;
    node->prev = NULL;
    node->data = value;

    // 返回
    return node;
}

// 创建双向链表
DoubleLinkedList *newDoubleLinkedList() {
    // 申请链表的内存
    DoubleLinkedList *list = malloc(sizeof(DoubleLinkedList));

    // 头节点
    DoubleLinkedListNode *head = _newDoubleLinkedListNode(0);

    // 尾结点
    DoubleLinkedListNode *tail = _newDoubleLinkedListNode(0);

    // 初始化
    list->head = head;
    list->tail = tail;

    // 返回
    return list;
}

释放双向链表内存

核心代码：

void freeDoubleLinkedList(DoubleLinkedList *list) {
    // 释放节点内存
    DoubleLinkedListNode *node = list->head->next;
    while (node->next != list->tail) {
        DoubleLinkedListNode *next = node->next;
        free(node);
        node = next;
    }
    // 释放首尾节点的内存
    free(list->head);
    free(list->tail);
    // 释放链表内存
    free(list);
}

double_linked_list.h

#ifndef ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H
#define ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

// 公共头文件
#include "stdio.h"
#include "string.h"
#include "stdlib.h"

// 双向链表的节点
typedef struct doubleLinkedListNode {
    int data;
    struct doubleLinkedListNode *next; // 下一个节点
    struct doubleLinkedListNode *prev; // 上一个节点
} DoubleLinkedListNode;

// 双向链表
typedef struct doubleLinkedList {
    DoubleLinkedListNode *head; // 头节点
    DoubleLinkedListNode *tail; // 尾节点
} DoubleLinkedList;

extern DoubleLinkedList *newDoubleLinkedList(); // 创建双向链表
extern void freeDoubleLinkedList(DoubleLinkedList *list); // 释放双向链表内存

#endif //ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

double_linked_list.c

#include "double_linked_list.h"

// 创建头节点
DoubleLinkedListNode *_newDoubleLinkedListNode(int value) {
    // 申请节点的空间
    DoubleLinkedListNode *node = malloc(sizeof(DoubleLinkedListNode));

    // 初始化
    node->next = NULL;
    node->prev = NULL;
    node->data = value;

    // 返回
    return node;
}

// 创建双向链表
DoubleLinkedList *newDoubleLinkedList() {
    // 申请链表的内存
    DoubleLinkedList *list = malloc(sizeof(DoubleLinkedList));

    // 头节点
    DoubleLinkedListNode *head = _newDoubleLinkedListNode(0);

    // 尾结点
    DoubleLinkedListNode *tail = _newDoubleLinkedListNode(0);

    // 初始化
    list->head = head;
    list->tail = tail;

    // 返回
    return list;
}

// 释放双向链表内存
void freeDoubleLinkedList(DoubleLinkedList *list) {
    // 释放节点内存
    DoubleLinkedListNode *node = list->head->next;
    while (node->next != list->tail) {
        DoubleLinkedListNode *next = node->next;
        free(node);
        node = next;
    }
    // 释放首尾节点的内存
    free(list->head);
    free(list->tail);
    // 释放链表内存
    free(list);
}

判断链表是否为空

核心代码：

int isEmptyDoubleLinkedList(DoubleLinkedList *list) {
    return list != NULL && list->head->next == list->tail;
}

优化创建链表的代码，让头节点下一个节点指向尾节点，尾节点的上一个节点指向头节点。

DoubleLinkedList *newDoubleLinkedList() {
    // 申请链表的内存
    DoubleLinkedList *list = malloc(sizeof(DoubleLinkedList));

    // 头节点
    DoubleLinkedListNode *head = newDoubleLinkedListNode(0);

    // 尾结点
    DoubleLinkedListNode *tail = newDoubleLinkedListNode(0);

    // 初始化
    list->head = head;
    list->tail = tail;

    // 关系
    list->head->next = list->tail;
    list->tail->prev = list->head;

    // 返回
    return list;
}

double_linked_list.h

#ifndef ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H
#define ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

// 公共头文件
#include "stdio.h"
#include "string.h"
#include "stdlib.h"

// 双向链表的节点
typedef struct doubleLinkedListNode {
    int data;
    struct doubleLinkedListNode *next; // 下一个节点
    struct doubleLinkedListNode *prev; // 上一个节点
} DoubleLinkedListNode;

// 双向链表
typedef struct doubleLinkedList {
    DoubleLinkedListNode *head; // 头节点
    DoubleLinkedListNode *tail; // 尾节点
} DoubleLinkedList;

extern DoubleLinkedList *newDoubleLinkedList(); // 创建双向链表
extern void freeDoubleLinkedList(DoubleLinkedList *list); // 释放双向链表内存
extern int isEmptyDoubleLinkedList(DoubleLinkedList *list); // 判断是否为空链表

#endif //ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

double_linked_list.c

#include "double_linked_list.h"

// 创建头节点
DoubleLinkedListNode *newDoubleLinkedListNode(int value) {
    // 申请节点的空间
    DoubleLinkedListNode *node = malloc(sizeof(DoubleLinkedListNode));

    // 初始化
    node->next = NULL;
    node->prev = NULL;
    node->data = value;

    // 返回
    return node;
}

// 创建双向链表
DoubleLinkedList *newDoubleLinkedList() {
    // 申请链表的内存
    DoubleLinkedList *list = malloc(sizeof(DoubleLinkedList));

    // 头节点
    DoubleLinkedListNode *head = newDoubleLinkedListNode(0);

    // 尾结点
    DoubleLinkedListNode *tail = newDoubleLinkedListNode(0);

    // 初始化
    list->head = head;
    list->tail = tail;

    // 关系
    list->head->next = list->tail;
    list->tail->prev = list->head;

    // 返回
    return list;
}

// 释放双向链表内存
void freeDoubleLinkedList(DoubleLinkedList *list) {
    // 释放节点内存
    DoubleLinkedListNode *node = list->head->next;
    while (node->next != list->tail) {
        DoubleLinkedListNode *next = node->next;
        free(node);
        node = next;
    }
    // 释放首尾节点的内存
    free(list->head);
    free(list->tail);
    // 释放链表内存
    free(list);
}

// 判断是否为空链表
int isEmptyDoubleLinkedList(DoubleLinkedList *list) {
    return list != NULL && list->head->next == list->tail;
}

获取链表的元素个数

给双向链表的结构加上size这个属性，每个新增的时候，这个数都+1，每次删除的时候都-1，这样这个属性的值代表的就是链表中元素的个数。

核心代码：

int sizeDoubleLinkedList(DoubleLinkedList *list) {
    return list->size;
}

double_linked_list.h

#ifndef ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H
#define ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

// 公共头文件
#include "stdio.h"
#include "string.h"
#include "stdlib.h"

// 双向链表的节点
typedef struct doubleLinkedListNode {
    int data;
    struct doubleLinkedListNode *next; // 下一个节点
    struct doubleLinkedListNode *prev; // 上一个节点
} DoubleLinkedListNode;

// 双向链表
typedef struct doubleLinkedList {
    DoubleLinkedListNode *head; // 头节点
    DoubleLinkedListNode *tail; // 尾节点
    int size; // 节点的个数
} DoubleLinkedList;

extern DoubleLinkedList *newDoubleLinkedList(); // 创建双向链表
extern void freeDoubleLinkedList(DoubleLinkedList *list); // 释放双向链表内存
extern int isEmptyDoubleLinkedList(DoubleLinkedList *list); // 判断是否为空链表
extern int sizeDoubleLinkedList(DoubleLinkedList *list); // 获取链表的元素个数

#endif //ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

double_linked_list.c

#include "double_linked_list.h"

// 创建头节点
DoubleLinkedListNode *newDoubleLinkedListNode(int value) {
    // 申请节点的空间
    DoubleLinkedListNode *node = malloc(sizeof(DoubleLinkedListNode));

    // 初始化
    node->next = NULL;
    node->prev = NULL;
    node->data = value;

    // 返回
    return node;
}

// 创建双向链表
DoubleLinkedList *newDoubleLinkedList() {
    // 申请链表的内存
    DoubleLinkedList *list = malloc(sizeof(DoubleLinkedList));

    // 头节点
    DoubleLinkedListNode *head = newDoubleLinkedListNode(0);

    // 尾结点
    DoubleLinkedListNode *tail = newDoubleLinkedListNode(0);

    // 初始化
    list->head = head;
    list->tail = tail;
    list->size = 0;

    // 关系
    list->head->next = list->tail;
    list->tail->prev = list->head;

    // 返回
    return list;
}

// 释放双向链表内存
void freeDoubleLinkedList(DoubleLinkedList *list) {
    // 释放节点内存
    DoubleLinkedListNode *node = list->head->next;
    while (node->next != list->tail) {
        DoubleLinkedListNode *next = node->next;
        free(node);
        node = next;
    }
    // 释放首尾节点的内存
    free(list->head);
    free(list->tail);
    // 释放链表内存
    free(list);
}

// 判断是否为空链表
int isEmptyDoubleLinkedList(DoubleLinkedList *list) {
    return list != NULL && list->head->next == list->tail;
}

// 获取链表的元素个数
int sizeDoubleLinkedList(DoubleLinkedList *list) {
    return list->size;
}

打印链表的内容

核心代码：

void printDoubleLinkedList(DoubleLinkedList *list) {
    if (list == NULL) {
        return;
    }
    if (list->head == NULL || list->head->next == NULL) {
        return;
    }
    DoubleLinkedListNode *current = list->head->next;
    while (current != list->tail) {
        printf("%d ", current->data);
        current = current->next;
    }
    printf("\n");
}

double_linked_list.h

#ifndef ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H
#define ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

// 公共头文件
#include "stdio.h"
#include "string.h"
#include "stdlib.h"

// 双向链表的节点
typedef struct doubleLinkedListNode {
    int data;
    struct doubleLinkedListNode *next; // 下一个节点
    struct doubleLinkedListNode *prev; // 上一个节点
} DoubleLinkedListNode;

// 双向链表
typedef struct doubleLinkedList {
    DoubleLinkedListNode *head; // 头节点
    DoubleLinkedListNode *tail; // 尾节点
    int size; // 节点的个数
} DoubleLinkedList;

extern DoubleLinkedList *newDoubleLinkedList(); // 创建双向链表
extern void freeDoubleLinkedList(DoubleLinkedList *list); // 释放双向链表内存
extern int isEmptyDoubleLinkedList(DoubleLinkedList *list); // 判断是否为空链表
extern int sizeDoubleLinkedList(DoubleLinkedList *list); // 获取链表的元素个数
extern void printDoubleLinkedList(DoubleLinkedList *list); // 打印链表的内容

#endif //ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

double_linked_list.c

#include "double_linked_list.h"

// 创建头节点
DoubleLinkedListNode *newDoubleLinkedListNode(int value) {
    // 申请节点的空间
    DoubleLinkedListNode *node = malloc(sizeof(DoubleLinkedListNode));

    // 初始化
    node->next = NULL;
    node->prev = NULL;
    node->data = value;

    // 返回
    return node;
}

// 创建双向链表
DoubleLinkedList *newDoubleLinkedList() {
    // 申请链表的内存
    DoubleLinkedList *list = malloc(sizeof(DoubleLinkedList));

    // 头节点
    DoubleLinkedListNode *head = newDoubleLinkedListNode(0);

    // 尾结点
    DoubleLinkedListNode *tail = newDoubleLinkedListNode(0);

    // 初始化
    list->head = head;
    list->tail = tail;
    list->size = 0;

    // 关系
    list->head->next = list->tail;
    list->tail->prev = list->head;

    // 返回
    return list;
}

// 释放双向链表内存
void freeDoubleLinkedList(DoubleLinkedList *list) {
    // 释放节点内存
    DoubleLinkedListNode *node = list->head->next;
    while (node->next != list->tail) {
        DoubleLinkedListNode *next = node->next;
        free(node);
        node = next;
    }
    // 释放首尾节点的内存
    free(list->head);
    free(list->tail);
    // 释放链表内存
    free(list);
}

// 判断是否为空链表
int isEmptyDoubleLinkedList(DoubleLinkedList *list) {
    return list != NULL && list->head->next == list->tail;
}

// 获取链表的元素个数
int sizeDoubleLinkedList(DoubleLinkedList *list) {
    return list->size;
}

// 打印链表的内容
void printDoubleLinkedList(DoubleLinkedList *list) {
    if (list == NULL) {
        return;
    }
    if (list->head == NULL || list->head->next == NULL) {
        return;
    }
    DoubleLinkedListNode *current = list->head->next;
    while (current != list->tail) {
        printf("%d ", current->data);
        current = current->next;
    }
    printf("\n");
}

添加元素到链表末尾

核心代码：

void appendDoubleLinkedList(DoubleLinkedList *list, int value) {
    if (list == NULL || list->head == NULL || list->tail == NULL) {
        return;
    }

    // 构造新节点
    DoubleLinkedListNode *node = newDoubleLinkedListNode(value);

    // 插入到末尾
    DoubleLinkedListNode *oldPrev = list->tail->prev;
    oldPrev->next = node;
    node->prev = oldPrev;
    node->next = list->tail;
    list->tail->prev = node;

    // 元素个数增加
    list->size++;
}

double_linked_list.h

#ifndef ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H
#define ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

// 公共头文件
#include "stdio.h"
#include "string.h"
#include "stdlib.h"

// 双向链表的节点
typedef struct doubleLinkedListNode {
    int data;
    struct doubleLinkedListNode *next; // 下一个节点
    struct doubleLinkedListNode *prev; // 上一个节点
} DoubleLinkedListNode;

// 双向链表
typedef struct doubleLinkedList {
    DoubleLinkedListNode *head; // 头节点
    DoubleLinkedListNode *tail; // 尾节点
    int size; // 节点的个数
} DoubleLinkedList;

extern DoubleLinkedList *newDoubleLinkedList(); // 创建双向链表
extern void freeDoubleLinkedList(DoubleLinkedList *list); // 释放双向链表内存
extern int isEmptyDoubleLinkedList(DoubleLinkedList *list); // 判断是否为空链表
extern int sizeDoubleLinkedList(DoubleLinkedList *list); // 获取链表的元素个数
extern void printDoubleLinkedList(DoubleLinkedList *list); // 打印链表的内容
extern void appendDoubleLinkedList(DoubleLinkedList *list, int value); // 将元素添加到链表末尾

#endif //ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

double_linked_list.c

#include "double_linked_list.h"

// 创建头节点
DoubleLinkedListNode *newDoubleLinkedListNode(int value) {
    // 申请节点的空间
    DoubleLinkedListNode *node = malloc(sizeof(DoubleLinkedListNode));

    // 初始化
    node->next = NULL;
    node->prev = NULL;
    node->data = value;

    // 返回
    return node;
}

// 创建双向链表
DoubleLinkedList *newDoubleLinkedList() {
    // 申请链表的内存
    DoubleLinkedList *list = malloc(sizeof(DoubleLinkedList));

    // 头节点
    DoubleLinkedListNode *head = newDoubleLinkedListNode(0);

    // 尾结点
    DoubleLinkedListNode *tail = newDoubleLinkedListNode(0);

    // 初始化
    list->head = head;
    list->tail = tail;
    list->size = 0;

    // 关系
    list->head->next = list->tail;
    list->tail->prev = list->head;

    // 返回
    return list;
}

// 释放双向链表内存
void freeDoubleLinkedList(DoubleLinkedList *list) {
    // 释放节点内存
    DoubleLinkedListNode *node = list->head->next;
    while (node->next != list->tail) {
        DoubleLinkedListNode *next = node->next;
        free(node);
        node = next;
    }
    // 释放首尾节点的内存
    free(list->head);
    free(list->tail);
    // 释放链表内存
    free(list);
}

// 判断是否为空链表
int isEmptyDoubleLinkedList(DoubleLinkedList *list) {
    return list != NULL && list->head->next == list->tail;
}

// 获取链表的元素个数
int sizeDoubleLinkedList(DoubleLinkedList *list) {
    return list->size;
}

// 打印链表的内容
void printDoubleLinkedList(DoubleLinkedList *list) {
    if (list == NULL) {
        return;
    }
    if (list->head == NULL || list->head->next == NULL) {
        return;
    }
    DoubleLinkedListNode *current = list->head->next;
    while (current != list->tail) {
        printf("%d ", current->data);
        current = current->next;
    }
    printf("\n");
}

// 将元素添加到链表末尾
void appendDoubleLinkedList(DoubleLinkedList *list, int value) {
    if (list == NULL || list->head == NULL || list->tail == NULL) {
        return;
    }

    // 构造新节点
    DoubleLinkedListNode *node = newDoubleLinkedListNode(value);

    // 插入到末尾
    DoubleLinkedListNode *oldPrev = list->tail->prev;
    oldPrev->next = node;
    node->prev = oldPrev;
    node->next = list->tail;
    list->tail->prev = node;

    // 元素个数增加
    list->size++;
}

main.c

#include "double_linked_list.h"

int main(void) {
    // 创建链表
    DoubleLinkedList *list = newDoubleLinkedList();

    // 添加数据
    appendDoubleLinkedList(list, 11);
    printDoubleLinkedList(list);

    appendDoubleLinkedList(list, 22);
    printDoubleLinkedList(list);

    appendDoubleLinkedList(list, 33);
    printDoubleLinkedList(list);

    // 释放链表
    freeDoubleLinkedList(list);

    return 0;
}

输出：

11
11 22
11 22 33

移除元素

核心代码：

int removeDoubleLinkedList(DoubleLinkedList *list, int value) {
    int index = -1;
    if (list == NULL || list->head == NULL || list->tail == NULL || list->size <= 0) {
        return index;
    }

    // 查找对应的元素
    DoubleLinkedListNode *current = list->head->next;
    while (current != list->tail) {
        index++;
        if (current->data == value) {
            break;
        }
        current = current->next;
    }

    // 如果找到了，则删除
    if (index >= 0 && index < list->size) {
        DoubleLinkedListNode *oldPrev = current->prev;
        DoubleLinkedListNode *oldNext = current->next;
        oldPrev->next = oldNext;
        oldNext->prev = oldPrev;
        free(current); // 记得释放节点的内存
    }

    // 元素个数减少
    list->size--;

    // 返回
    return index;
}

double_linked_list.h

#ifndef ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H
#define ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

// 公共头文件
#include "stdio.h"
#include "string.h"
#include "stdlib.h"

// 双向链表的节点
typedef struct doubleLinkedListNode {
    int data;
    struct doubleLinkedListNode *next; // 下一个节点
    struct doubleLinkedListNode *prev; // 上一个节点
} DoubleLinkedListNode;

// 双向链表
typedef struct doubleLinkedList {
    DoubleLinkedListNode *head; // 头节点
    DoubleLinkedListNode *tail; // 尾节点
    int size; // 节点的个数
} DoubleLinkedList;

extern DoubleLinkedList *newDoubleLinkedList(); // 创建双向链表
extern void freeDoubleLinkedList(DoubleLinkedList *list); // 释放双向链表内存
extern int isEmptyDoubleLinkedList(DoubleLinkedList *list); // 判断是否为空链表
extern int sizeDoubleLinkedList(DoubleLinkedList *list); // 获取链表的元素个数
extern void printDoubleLinkedList(DoubleLinkedList *list); // 打印链表的内容
extern void appendDoubleLinkedList(DoubleLinkedList *list, int value); // 将元素添加到链表末尾
extern int removeDoubleLinkedList(DoubleLinkedList *list, int value); // 从链表中移除元素，成功返回其索引，失败返回-1

#endif //ZDPC_ALGORITHM_DEV_DOUBLE_LINKED_LIST_H

double_linked_list.c

#include "double_linked_list.h"

// 创建头节点
DoubleLinkedListNode *newDoubleLinkedListNode(int value) {
    // 申请节点的空间
    DoubleLinkedListNode *node = malloc(sizeof(DoubleLinkedListNode));

    // 初始化
    node->next = NULL;
    node->prev = NULL;
    node->data = value;

    // 返回
    return node;
}

// 创建双向链表
DoubleLinkedList *newDoubleLinkedList() {
    // 申请链表的内存
    DoubleLinkedList *list = malloc(sizeof(DoubleLinkedList));

    // 头节点
    DoubleLinkedListNode *head = newDoubleLinkedListNode(0);

    // 尾结点
    DoubleLinkedListNode *tail = newDoubleLinkedListNode(0);

    // 初始化
    list->head = head;
    list->tail = tail;
    list->size = 0;

    // 关系
    list->head->next = list->tail;
    list->tail->prev = list->head;

    // 返回
    return list;
}

// 释放双向链表内存
void freeDoubleLinkedList(DoubleLinkedList *list) {
    // 释放节点内存
    DoubleLinkedListNode *node = list->head->next;
    while (node->next != list->tail) {
        DoubleLinkedListNode *next = node->next;
        free(node);
        node = next;
    }
    // 释放首尾节点的内存
    free(list->head);
    free(list->tail);
    // 释放链表内存
    free(list);
}

// 判断是否为空链表
int isEmptyDoubleLinkedList(DoubleLinkedList *list) {
    return list != NULL && list->head->next == list->tail;
}

// 获取链表的元素个数
int sizeDoubleLinkedList(DoubleLinkedList *list) {
    return list->size;
}

// 打印链表的内容
void printDoubleLinkedList(DoubleLinkedList *list) {
    if (list == NULL) {
        return;
    }
    if (list->head == NULL || list->head->next == NULL) {
        return;
    }
    DoubleLinkedListNode *current = list->head->next;
    while (current != list->tail) {
        printf("%d ", current->data);
        current = current->next;
    }
    printf("\n");
}

// 将元素添加到链表末尾
void appendDoubleLinkedList(DoubleLinkedList *list, int value) {
    if (list == NULL || list->head == NULL || list->tail == NULL) {
        return;
    }

    // 构造新节点
    DoubleLinkedListNode *node = newDoubleLinkedListNode(value);

    // 插入到末尾
    DoubleLinkedListNode *oldPrev = list->tail->prev;
    oldPrev->next = node;
    node->prev = oldPrev;
    node->next = list->tail;
    list->tail->prev = node;

    // 元素个数增加
    list->size++;
}

// 从链表中移除元素
int removeDoubleLinkedList(DoubleLinkedList *list, int value) {
    int index = -1;
    if (list == NULL || list->head == NULL || list->tail == NULL || list->size <= 0) {
        return index;
    }

    // 查找对应的元素
    DoubleLinkedListNode *current = list->head->next;
    while (current != list->tail) {
        index++;
        if (current->data == value) {
            break;
        }
        current = current->next;
    }

    // 如果找到了，则删除
    if (index >= 0 && index < list->size) {
        DoubleLinkedListNode *oldPrev = current->prev;
        DoubleLinkedListNode *oldNext = current->next;
        oldPrev->next = oldNext;
        oldNext->prev = oldPrev;
        free(current); // 记得释放节点的内存
    }

    // 元素个数减少
    list->size--;

    // 返回
    return index;
}

main.c

#include "double_linked_list.h"

int main(void) {
    // 创建链表
    DoubleLinkedList *list = newDoubleLinkedList();

    // 添加数据
    appendDoubleLinkedList(list, 11);
    appendDoubleLinkedList(list, 22);
    appendDoubleLinkedList(list, 33);
    printDoubleLinkedList(list);
    printf("元素个数：%d\n",list->size);

    // 删除数据
    removeDoubleLinkedList(list,22);
    printDoubleLinkedList(list);
    printf("元素个数：%d\n",list->size);

    // 释放链表
    freeDoubleLinkedList(list);

    return 0;
}

输出：

11 22 33
元素个数：3
11 33
元素个数：2