C語言反轉鏈表

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原創文章，拒絕轉載

主要的思想是使用三個標記指標：preNode、curNode、nextNode，每次將curNode的next設為preNode，然後如果此時nextNode為空白，跳出迴圈，將鏈表頭指標的next設為NULL，返回鏈表尾指標；否則，preNode = curNode，curNode=nextNode，nextNode=nextNode -> next。

實現如下：

#include <stdio.h>#include <malloc.h>typedef struct Node{    int val;    struct Node *next;} Node;Node* reverse_list(Node *headNode) {    if (headNode == NULL) {        return NULL;    }    if (headNode -> next == NULL) {        return headNode;    }    if (headNode -> next -> next == NULL) {        Node* resNode = headNode -> next;        resNode -> next = headNode;        headNode -> next = NULL;        return resNode;    }    Node *preNode = headNode;    Node *curNode = preNode -> next;    Node *nextNode = curNode -> next;    for ( ; ; ) {        curNode -> next = preNode;        if (nextNode == NULL) {            break;        }        preNode = curNode;        curNode = nextNode;        nextNode = curNode -> next;    }    headNode -> next = NULL;    return curNode;}int main(int argc, char const *argv[]){    int n;    int temp;    int i;    scanf("%d", &n);    if (n <= 0)        return 0;        Node* headNode = (Node*)malloc(sizeof(Node));    scanf("%d", &temp);    headNode -> val = temp;    headNode -> next = NULL;    Node *curNode = headNode;    for (i = 1; i < n; i++) {        scanf("%d", &temp);        curNode -> next = (Node*)malloc(sizeof(Node));        curNode -> next -> val = temp;        curNode -> next -> next = NULL;        curNode = curNode -> next;    }    curNode = reverse_list(headNode);    Node *tempNode;    while (curNode) {        tempNode = curNode;        curNode = curNode -> next;        printf("%d ", tempNode -> val);        free(tempNode);    }    printf("\n");    return 0;}

C語言反轉鏈表