linux C学习笔记03--单链表

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

typedef struct link{
int data;
struct link* next;
}*LINK;

int insert_link(LINK* head,int data);
int print(LINK head);
int delete_node(LINK *head,int n);
int find_node(LINK head,int n);

int insert_link(LINK* head,int data)
{
LINK node = (LINK)malloc(sizeof(struct link));
LINK tmp = NULL;

if(node != NULL)
{
node->data = data;
node->next = NULL;
}
else
{
printf("malloc new node error!\n");
return -1;
}

if(*head == NULL)
{
*head = node;
return 0;
}

tmp = *head;
while(tmp->next != NULL)    //find ending node
{
tmp = tmp->next;
}
tmp->next = node;

return 0;
}

int print(LINK head)
{
LINK tmp = head;
while(tmp != NULL)
{
printf("%d \n",tmp->data);
tmp = tmp->next;
}

return 0;
}

int    delete_node(LINK *head,int n)    //delete the node of index is n
{
LINK tmp = *head;
LINK save = tmp;
int i = 0;

if(n == 1)
{
tmp = tmp->next;
free(save);
*head = tmp;
return 0;
}

while(tmp != NULL)
{
if(i == n-1)
{
save->next = tmp->next;
free(tmp);
break;
}

save = tmp;
tmp = tmp->next;
i++;
}

if(n-1 > i)
{
printf("error: delete %d is out of length\n",n);
return -1;
}

return 0;
}

int find_node(LINK head,int n)
{
LINK tmp = head;
int data = 0;
int i = 0;

while(tmp != NULL)
{
if(i == n-1)
{
data = tmp->data;
break;
}
tmp = tmp->next;
i++;
}

if(n-1 > i)
{
printf("find_node error: out of link length\n");
return -1;
}

return data;
}

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

typedef struct link{
int data;
struct link* next;
}*LINK;

extern int insert_link(LINK* head,int data);
extern int print(LINK head);
extern int delete_node(LINK *head,int n);
extern int find_node(LINK head,int n);

int main(int argc,char* argv[])
{
LINK phead = NULL;

insert_link(&phead,1);
insert_link(&phead,2);
insert_link(&phead,3);
insert_link(&phead,4);
insert_link(&phead,5);
insert_link(&phead,6);

print(phead);
delete_node(&phead,1);                //delete the node by index
print(phead);
delete_node(&phead,2);                //delete the node by index
print(phead);
delete_node(&phead,1);                //delete the node by index
print(phead);

printf("find node 6 is %d\n",find_node(phead,6));        //finding the node by index

return 0;
}