单链表逆置（就地逆序） C语言实现

LinkList.h

#ifndef LINKLIST_H#define LINKLIST_H typedef int ElemType;typedef struct LNode{ElemType *data;struct LNode *next;int length;}LNode, *LinkList;LinkList initList();void insertList(LinkList l, ElemType *data, int sizeOfData);int length(LinkList l);void reverse(LinkList l);#endif 

 

LinkList.c

#include "LinkList.h"#include <stdlib.h>#include <string.h>//************************************// Method: initList// FullName: initList// Access: public // Returns: LinkList// Qualifier://************************************LinkList initList(){LinkList l = 0;l = (LinkList)malloc(sizeof(LNode));if(l == NULL)return NULL;l->data = 0;l->next = NULL;l->length = 0;return l;}//************************************// Method: insertList// FullName: insertList// Access: public // Returns: void// Qualifier:// Parameter: LinkList l// Parameter: ElemType * data// Parameter: int sizeOfData//************************************void insertList(LinkList l, ElemType *data, int sizeOfData){LNode *n = 0;if(l == NULL || data == NULL)return;n = (LNode *)malloc(sizeof(LNode));if(n == NULL)return;n->data = (ElemType *)malloc(sizeof(ElemType));if(n->data == NULL){free(n->data);free(n);return;}memcpy(n->data, data, sizeOfData);n->next = l->next;l->next = n;l->length++;}//************************************// Method: length// FullName: length// Access: public // Returns: int// Qualifier:// Parameter: LinkList l//************************************int length(LinkList l){if(l == NULL)return 0;return l->length;}//************************************// Method: reverse// FullName: reverse// Access: public // Returns: void// Qualifier:// Parameter: LinkList l//************************************void reverse(LinkList l){LinkList p, q, r;if(l == NULL)return;p = l->next;q = p->next;//q为p下一个节点while(q){r = q->next;//r为q下一个节点q->next = p;//指针回指p = q;q = r;//p, q后移 *关键是对指针间赋值的理解*}l->next = p;} 

 

main.c

#include "LinkList.h"#include <stdio.h>int main(){ElemType num1 = 1, num2 = 2, num3 = 3;LinkList l = initList();LinkList l2 = initList();insertList(l, &num1, sizeof(ElemType));insertList(l, &num2, sizeof(ElemType));insertList(l, &num3, sizeof(ElemType));reverse(l);return 0;}