练习2.5
//试编写算法将带头结点的单链表就地逆置
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
using namespace std;
typedef struct Lnode{
int data;
struct Lnode *next;
}Lnode,*LinkList;
//初始化带头节点的单链表
void init_LinkList(LinkList &L){
int x;
L = (LinkList)malloc(sizeof(Lnode));
Lnode *r = L,*p;
cout<<"请输入数据（-1退出）：";
cin>>x;
while(x != -1){
p = (Lnode*)malloc(sizeof(Lnode));
p->data = x;
p->next = NULL;
r->next = p;
cout<<p->data<<" "<<p<<" "<<p->next<<endl;
r = p;
cout<<"请输入数据（-1退出）：";
cin>>x;
}
}
//逆置单链表,采用头插法
void reverse_LinkList(LinkList &L){
Lnode *r,*p;
//p指向表头下一个，即要插入位置 ,r指向原序表
r = L->next;
L->next = NULL;
while(r != NULL){
p = r;
r = r->next;
p->next = L->next;
L->next = p;
}
}
int main(){
LinkList L;
init_LinkList(L);
Lnode *p;
p = L->next;
while(p!= NULL){
cout<<p->data<<" ";
p = p->next;
}
cout<<endl;
p = L;
reverse_LinkList(p);
p = L->next;
while(p!= NULL){
cout<<p->data<<" ";
p = p->next;
}
}
