线性表 之 链表反转

//时间复杂度 O(N)

#include <stdio.h>

#include <stdlib.h>
struct node{
int data;
struct node* next;
};
static void reverse(struct node** head_ref){
struct node* prev = NULL;
struct node* current = *head_ref;
struct node* next;
while(current != NULL){
next = current->next;
current->next = prev;
prev = current;
current = next;
}
*head_ref = prev;
}
void push(struct node** head_ref,int new_data){
struct node* new_node = (struct node*) malloc(sizeof(struct node));
new_node->data = new_data;
new_node->next = (*head_ref);
(*head_ref) = new_node;
}
void printlist(struct node* head){
struct node *temp = head;
while(temp != NULL){
printf("%d ",temp->data);
temp = temp->next;
}
}
int main(){
struct node* head = NULL;
push(&head,20);
push(&head,4);
push(&head,15);
push(&head,85);
push(&head,60);
push(&head,100);
printlist(head);
reverse(&head);
printf("\n Reversed linked list \n");
printlist(head);


return 0;
}