使用指针操作列表时，

#include <stdio.h>
#include <stdlib.h>

struct node{
int data;
struct node *next;
} *head;

//sorted link-list
void insert(struct node *new_node){
struct node *cur = head, *pre = NULL;
while(cur != NULL && cur->data < new_node->data){
pre = cur;
cur = cur->next;
}

new_node->next = cur;
if(pre == NULL)
head = new_node;
else
pre->next = new_node;
}

//use pointer to pointer can make things easier
void insert2(struct node *new_node){
struct node **linkp = &head;
while(*linkp !=NULL && (*linkp)->data < new_node->data){
linkp = &(*linkp)->next;
}

new_node->next = *linkp;
*linkp = new_node;
}

void show(){
struct node *p = head;
while(p){
printf("%d , ", p->data);
p = p->next;
}
}

int main(){
int i;
struct node ns[] = {
{80, NULL},
{8, NULL},
{1, NULL},
{10, NULL},
};
for(i = 0; i < 4; i++){
insert2(&ns[i]);
}
show();

return 0;
}