C语言使用栈反转链表
为什么代码1可以完成,而代码2无法完成
代码1
#include<stdio.h>
#include<stdlib.h>
#define max_size 101
typedef struct
{
char data[max_size];
int first;
}stack;
struct node
{
int data;
struct node* next;
};
struct node* head;
void head_insert(int data){
struct node* temp = (struct node*)malloc(sizeof(struct node));
temp->data = data;
temp->next = NULL;
temp->next = head;
head = temp;
}
void print(){
struct node* temp = head;
while (temp != NULL)
{
printf(" %d",temp->data);
temp = temp->next;
}
printf("\n");
}
void init(stack *s){
s->first = -1;
}
void push(stack *s,char str){
if (s->first == max_size-1)
{
return;
}
s->data[s->first++] = str;
}
char top(stack *s){
return s->data[--s->first];
}
void reverse(){
stack s;
init(&s);
struct node* temp = head;
while (temp != NULL)
{
push(&s,temp->data);
temp = temp->next;
}
temp = head;
while (temp != NULL)
{
temp->data = top(&s);
temp = temp->next;
}
}
int main(){
//创建一个链表
head = NULL;
head_insert(2);
head_insert(3);
head_insert(4);
head_insert(5);
print();// 5 4 3 2
//反转一个链表
reverse();
print();// 2 3 4 5
}
代码2
#include<stdio.h>
#include<stdlib.h>
#define max_size 101
typedef struct
{
char data[max_size];
int first;
}stack;
struct node
{
int data;
struct node* next;
};
struct node* head;
void head_insert(int data){
struct node* temp = (struct node*)malloc(sizeof(struct node));
temp->data = data;
temp->next = NULL;
temp->next = head;
head = temp;
}
void print(){
struct node* temp = head;
while (temp != NULL)
{
printf(" %d",temp->data);
temp = temp->next;
}
printf("\n");
}
void init(stack *s){
s->first = -1;
}
void push(stack *s,char str){
if (s->first == max_size-1)
{
return;
}
s->data[s->first++] = str;
}
void pop(stack *s){
if (s->first == -1)
{
return;
}
s->first--;
}
char top(stack *s){
return s->data[s->first];
}
void reverse(){
stack s;
init(&s);
struct node* temp = head;
while (temp != NULL)
{
push(&s,temp->data);
temp = temp->next;
}
temp = head;
while (temp != NULL)
{
temp->data = top(&s);
pop(&s);
temp = temp->next;
}
}
int main(){
//创建一个链表
head = NULL;
head_insert(2);
head_insert(3);
head_insert(4);
head_insert(5);
print();// 5 4 3 2
//反转一个链表
reverse();
print();// 2 3 4 5
}