单链表反转

#include <stdio.h>

#include <stdlib.h>

typedef struct _Node{

int data;

_Node* next;

}Node, *LinkList;

//一般反转

LinkList Reverse(LinkList &head)

{

if(head == NULL)

return NULL;

Node *pre, *cur, *next;

pre = head;

cur = head->next;

while(cur)

{

next = cur->next;

cur->next = pre;

pre = cur;

cur = next;

}

head->next = NULL;

head = pre;

return head;

}

//递归反转

//注意最后返回值的next域置NULL

LinkList RReverse(LinkList p, LinkList &head)

{

if( (p==NULL) || (p->next==NULL) )

{

head = p;

return p;

}

else

{

LinkList tmp = RReverse(p->next, head);

tmp->next = p;

return p;

}

}

bool CreateList(LinkList &head, const int *data, const int len)

{

Node *cur = NULL;

Node *next = NULL;

int i;

cur = (LinkList)malloc(sizeof(Node));

if(cur == NULL)

return false;

cur->data = data[0];

cur->next = NULL;

head = cur;

for(i=1; i<len; i++)

{

next = (LinkList)malloc(sizeof(Node));

if(next == NULL)

return false;

next->data = data[i];

next->next = NULL;

cur->next = next;

cur = cur->next;

}

return true;

}

void PrintList(LinkList head)

{

while(head != NULL)

{

printf(" %d", head->data);

head = head->next;

}

}

void main( void )

{

int data[] = {1, 2, 3, 4, 5, 6};

int len = sizeof(data)/sizeof(int);

LinkList head;

if( !CreateList(head, data, len) )

{

printf("创建链表失败！\n");

return;

}

printf("反转前：");

PrintList(head);

printf("\n");

Reverse(head);

printf("反转后：");

PrintList(head);

printf("\n");

LinkList tail = RReverse(head, head);

tail->next = NULL;
//没有这条语句，则反转后的最后两个节点会形成环

printf("二次反转后：");

PrintList(head);

printf("\n");

}