题目：单链表取反
#include <stdlib.h>
#include <stdio.h>
typedef struct node *list;
typedef struct node *position;
typedef struct node *ListNode;
typedef struct node
{
int data;
position next;
}node;
static list init_list(void);
static void delete_list(list L);
static int isempty(list L);
static void insert_node(position L,int data);
static void delete_node(list L,position P);
static position find_last(list L);
static position find_value(list L,int data);
static position find_pre(list L,position P );
static void print(list L);
list init_list(void){
list L = (list)malloc(sizeof(node));
L->next = NULL;
return L;
}
void delete_list(list L){
position P ,next;
P = L;
do{
next = P->next;
free(P);
P = next;
}while(next != NULL);
}
int isempty(list L){
return (L->next == NULL);
}
void insert_node(position P,int data){
position tem ;
tem = (position)malloc(sizeof(node));
tem->data = data;
tem->next = P->next;
P->next = tem;
}
void delete_node(list L,position P){
position pre ;
pre = find_pre( L, P);
if(pre != NULL)
{
pre->next = P->next;
free(P);
}
else
{
printf("delete_node:p is not in the list!\n");
}
}
position find_last(list L){
position P;
P=L;
while(P->next != NULL)
{
P = P->next;
}
return P;
}
position find_value(list L,int data){
position P ;
P = L;
while(P->next != NULL)
{
P = P->next;
if(P->data == data)
return P;
}
return NULL;
}
position find_pre(list L,position P ){
position tem ;
tem = L;
while(tem->next != NULL)
{
if(tem->next == P)
return tem;
tem = tem->next;
}
return NULL;
}
void print(list L){
position P;
if(isempty( L))
{
printf("print: L is a null list!\n");
return ;
}
P = L;
while(P->next !=NULL)
{
P = P->next;
printf("print:%p : %d \n",P,P->data);
}
printf("\n");
}
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* struct ListNode *next;
* };
*/
ListNode reverseList( ListNode head) {
if((head == NULL)||(head->next == NULL) )
return head;
ListNode cur= head;
ListNode tempt=NULL;
while (cur->next!=NULL&& cur!=NULL)
{
tempt=cur->next;
cur->next=tempt->next;
tempt->next=head;
head=tempt;
tempt=cur->next;
}
return head;
}
int main()
{
int a[6]= {1,2,3,4,5,6};
int i=0;
list L,L1;
L = init_list();
print(L);
printf("insert node\n");
for(i=0;i<6;i++)
{
insert_node( L,a[i]);
}
print( L);
L1 = reverseList(L);
print( L1);
}