回归C基础

实现一个单向链表，并有逆序功能 （大学数据结构经常是这么入门的）

//定义单链表结构体

typedef struct Node{

    int value;

    struct Node *next;

}Node;

//创建链表

Node* createNode(int value,Node *next){

    Node *node = malloc(sizeof(Node));

    node->value = value;

    node->next = next;

    return node;

}

//打印链表

void printList(Node *list){

    for (Node *node = list; node != NULL; node = node->next) {

        printf("current node value %d \n",node->value);

    }

}

//反转链表

Node* reverse(Node *listNode){

    Node *reList = NULL;

    Node *tmp;

    while (listNode != NULL) {

        tmp = malloc(sizeof(Node));

        //逆转之后，原链表的头结点就是新链表的尾结点

        //如果不是第一个结点，则本次产生的新结点是上次结点的前一个

        if (reList == NULL) {

            tmp->next = NULL;

        }else{

            tmp->next = reList;

        }

        tmp->value = listNode->value;

        reList = tmp;

        listNode = listNode->next;

    }

    //原链表的最后一个结点是新链表的头结点

    return reList;

}

//销毁

void destroyList(Node *list){

    Node *tmp;

    while (list != NULL) {

        tmp = list;

        list = list->next;

        free(tmp);

    }

    printf("链表销毁\n");

}

测试打印结果

int main(int argc, const char * argv[]) {

    @autoreleasepool {

        Node *first = createNode(0, NULL);

        Node *list = first;

        first->next = createNode(2, NULL);

        first = first->next;

        first->next = createNode(3, NULL);

        first = first->next;

        first->next = createNode(4, NULL);

        first = first->next;

        first->next = createNode(7, NULL);

        first = first->next;

        printf("源数据:\n");

        printList(list);

        printf("反转后数据:\n");

        list = reverse(list);

        printList(list);

        destroyList(list);

    }

    return 0;

}

结果: