C语言复习数据结构之带头节点的双向不循环链表

结构体

typedef struct DListNode {
    _Data value;
    struct DListNode *pre;
    struct DListNode *next;
} *pNode, Node;

函数声明

pNode createNode(_Data value);          //创建节点
pNode addNode(pNode head, _Data value);//添加节点
pNode createHead();                     //创建头节点
pNode destoryList(pNode head);          //销毁节点
int listSize(pNode head);               //获取链表长度
void printList(pNode head);             //打印链表信息
pNode findNodeByValue(pNode head, _Data value);//查找数据
pNode findNodeByIndex(pNode head, int index);  //根据索引查找数据
void deleteNodeByValue(pNode head, _Data value);//删除第一次出现的某值
void deleteNodeByIndex(pNode head, int index);//删除索引指向的节点
int findValueFormList(pNode head, _Data value);//查找某值第一次出现的位置

函数体实现

#include 
#include 

pNode createNode(_Data value) {
    pNode node = (pNode) malloc(sizeof(Node));
    node->next = NULL;
    node->pre = NULL;
    node->value = value;

    return node;
}

pNode addNode(pNode head, _Data value) {
    pNode temp = head;
    while (temp->next != NULL) {
        temp = temp->next;
    }

    pNode beAdd = createNode(value);

    temp->next = beAdd;
    beAdd->pre = temp;
    beAdd->next = NULL;
}

pNode createHead() {
    return createNode(0);
}

pNode destoryList(pNode head) {
    pNode temp = head;
    while (temp != NULL) {
        head = temp->next;
        free(temp);
        temp = head;
    }

    return NULL;
}

int listSize(pNode head) {
    pNode temp = head->next;
    int count = 0;

    while (temp != NULL) {
        count++;
        temp = temp->next;
    }

    return count;
}

void printList(pNode head) {
    if (head != NULL) {
        printf("链表状态：\n");
        printf("--->链表大小：%d\n", listSize(head));
        printf("--->链表数据：Head<->");

        pNode temp = head->next;
        while (temp != NULL) {
            printf("%d<->", temp->value);
            temp = temp->next;
        }

        printf("NULL\n");
    }
}

pNode findNodeByValue(pNode head, _Data value) {
    if (head != NULL) {
        pNode temp = head->next;
        while (temp != NULL) {
            if (temp->value == value) {
                return temp;
            }

            temp = temp->next;
        }
    }

    return NULL;
}

pNode findNodeByIndex(pNode head, int index) {
    int count = 0;
    pNode temp;
    if (head != NULL) {
        temp = head->next;
        while (count < index && temp != NULL) {
            temp = temp->next;
            count++;
        }
    }

    return temp;
}

void deleteNodeByValue(pNode head, _Data value) {
    pNode beDelete = findNodeByValue(head, value);

    if (beDelete != NULL) {
        beDelete->pre->next = beDelete->next;
        if (beDelete->next != NULL)
            beDelete->next->pre = beDelete->pre;
        free(beDelete);
    }
}

void deleteNodeByIndex(pNode head, int index) {
    if (index > listSize(head)) {
        return;
    } else {
        pNode beDelete = findNodeByIndex(head, index);
        beDelete->pre->next = beDelete->next;
        if (beDelete->next != NULL)
            beDelete->next->pre = beDelete->pre;
        free(beDelete);
    }
}

int findValueFormList(pNode head, _Data value) {
    if (head != NULL) {
        pNode temp = head->next;
        int count = 0;

        while (temp != NULL) {
            count++;

            if (temp->value == value) {
                return count;
            }

            temp = temp->next;
        }
    }

    return -1;

测试代码：

int main() {
    pNode head = createHead();
    printList(head);
    addNode(head, 6);
    printList(head);
    printf("6第一次出现的位置：%d\n", findValueFormList(head, 6));
    addNode(head, 7);
    printList(head);
    deleteNodeByIndex(head, 1);
    printList(head);
    deleteNodeByValue(head, 6);
    printList(head);
    head = destoryList(head);
    printList(head);
}

测试结果