通用单链表C实现

/*************************************************************************
> File Name: linklist.c
> Author: yaomianwei
> Mail: 13642245956@163.com
> Created Time: Fri 20 May 2016 08:58:31 PM CST
************************************************************************/

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

#define return_if_fail(p) if(!(p)) \
{printf("%s:%d Warning: "#p" failed.\n",\
__func__, __LINE__); return;}

#define return_val_if_fail(p,ret) if(!(p)) \
{printf("%s:%d Warning: "#p" failed.\n",\
__func__, __LINE__); return (ret);}

typedef enum Ret
{
RET_OK,
RET_ERR,
}Ret;

typedef void* ElemType;

typedef struct Node
{
ElemType data;
struct Node *next;
}Node;

typedef struct Node* LinkList;

typedef void (*PrintFunc)(ElemType e);

Ret linklist_init(LinkList* L)
{
*L = (LinkList)malloc(sizeof(Node));

return_val_if_fail(L, RET_ERR);

(*L)->next = NULL;

return RET_OK;
}

size_t get_linklist_length(LinkList L)
{
size_t countRet = 0;

LinkList p = L->next;

while(p)
{
countRet++;

p = p->next;
}

return countRet;
}

void print_int(ElemType e)
{
printf("%d  ",(int)e);
}

Ret linklist_show(LinkList L, PrintFunc print)
{
LinkList p = NULL;

p = L->next;

while(p)
{
print(p->data);

p = p->next;
}
printf("\n");

return RET_OK;
}

Ret linklist_insert_from_pos(LinkList L, size_t pos, ElemType e)
{
size_t count = 1;

LinkList p, new;

p = L;

while(p && count < pos)
{
p = p->next;

++count;
}
if(!p || count > pos)
{
return RET_ERR;
}

new = (LinkList)malloc(sizeof(Node));

return_val_if_fail(new, RET_ERR);

new->data = e;

new->next = p->next;

p->next = new;

return RET_OK;
}

Ret linklist_del_from_pos(LinkList L, size_t pos, ElemType* e)
{
size_t count = 1;

LinkList p = L;

while(p->next && count < pos)
{
p = p->next;

++count;
}
if(!(p->next) || count > pos)
{
return RET_ERR;
}

LinkList q = p->next;

p->next = q->next;

*e = q->data;

free(q);

return RET_OK;
}

LinkList linklist_reverse(LinkList L)
{
LinkList p, q, r;

p = L->next;

q = p->next;

p->next = NULL;

while(q)
{
r = q->next;

q->next = p;

p = q;

q = r;
}

L->next = p;

return L;
}

Ret linklist_insert_from_head(LinkList L, ElemType e)
{
LinkList new = (LinkList)malloc(sizeof(Node));

return_val_if_fail(new, RET_ERR);

new->data = e;

new->next = L->next;

L->next = new;

return RET_OK;
}

Ret linklist_insert_from_tail(LinkList L, ElemType e)
{
size_t listLen = get_linklist_length(L);

size_t pos;

LinkList p = L, new;

new = (LinkList)malloc(sizeof(Node));

return_val_if_fail(new, RET_ERR);

new->data = e;

for(pos = 0; pos < listLen; pos++)
{
p = p->next;
}

new->next = p->next;

p->next = new;

return RET_OK;
}

Ret linklist_get_elem(LinkList L, size_t pos, ElemType* e)
{
size_t count = 1;

LinkList p;

p = L->next;

while(p && count < pos)
{
p = p->next;

++count;
}

if(!p || count > pos)
{
return RET_ERR;
}

*e = p->data;

return RET_OK;
}

Ret linklist_clear(LinkList L)
{
LinkList p, q;

p = L->next;

while(p)
{
q = p->next;

free(p);

p = q;
}

L->next = NULL;

return RET_OK;
}

Ret linklist_destroy(LinkList L)
{
LinkList p, q;

p = L;

while(p)
{
q = p->next;

free(p);

p = q;
}

return RET_OK;
}

int main(int argc, char** argv)
{
LinkList L = NULL;

Ret ret = linklist_init(&L);
if(ret == RET_ERR)
{
return -1;
}

int i;
for(i = 0; i < 20; i++)
linklist_insert_from_pos(L, 1, (void*)i);

linklist_show(L, print_int);

size_t LLen = get_linklist_length(L);

printf("linklist's length is %d\n", LLen);

int data = 50;

linklist_insert_from_pos(L, 2, (void*)data);

linklist_show(L, print_int);

LLen = get_linklist_length(L);

printf("linklist's length is %d\n", LLen);

linklist_del_from_pos(L, 23, (void*)&data);

linklist_show(L, print_int);

LLen = get_linklist_length(L);

printf("linklist's length is %d\n", LLen);

printf("del num:%d\n", data);

L = linklist_reverse(L);

printf("reverse show:\n");

linklist_show(L, print_int);

size_t pos = 4;

linklist_get_elem(L, pos, (ElemType*)&data);

printf("get num where pos is 4:%d\n", data);

for(i = 30; i < 50; i++)
{
linklist_insert_from_head(L, (ElemType)i);
}

printf("insert data from head\n");

linklist_show(L, print_int);

for(i = 70; i < 90; i++)
{
linklist_insert_from_tail(L, (ElemType)i);
}

printf("insert data from tail\n");

linklist_show(L, print_int);

linklist_clear(L);

linklist_destroy(L);

return 0;
}