C-language bidirectional linked list

typedef int ELEMTYPE;

typedef struct _NODE

{

Elemtype value;

struct _node* pnext;

struct _node* prev;

}node, *pnode;

Create a doubly linked list

Pnode create_double_list (int count)

{

Pnode pn = NULL;

Pnode PB = NULL;

Pnode Phead = (pnode) malloc (sizeof (node));

printf ("Please enter a value for the 1th node:");

scanf ("%d", &phead->value);

if (count = = 1)

{

Phead->pnext = Phead->prev = Phead;

return phead;

}

Else

{

int i = 0;

//Phead->pnext = Phead->prev = NULL;

PN = Phead;

for (i = 1; i < count; ++i)

{

PB = (pnode) malloc (sizeof (node));

printf ("Please enter the value of%d nodes:", (i + 1));

scanf ("%d", &pb->value);

Pn->pnext = PB;

Pb->prev = PN;

PN = PB;

}

Pn->pnext = Phead;

Phead->prev = PN;

return phead;

}

}

Positive sequence traversal

void Printf_next_list_value (Pnode pnode)

{

int i = 0;

Pnode pn = Pnode;

printf ("The result of a positive sequence traversal is:");

while (I < g_count)

{

if (Pn->pnext = = PN)

{

printf ("%3d", Pn->value);

}

if (pn->pnext! = PN)

{

printf ("%3d", Pn->value);

PN = pn->pnext;

}

i++;

}

printf ("\ n");

}

This article is from the "Linux_woniu" blog, make sure to keep this source http://llu1314.blog.51cto.com/5925801/1965327

C-language bidirectional linked list