目录
一、栈基础知识
在上一篇的顺序栈中已经讲解过了栈的基础知识，这篇主要来讲一下栈的另一种结构 --- 链式栈，本文使用的链表结构为单向链表，当然了也可以使用双向链表来实现；对于栈的入栈采用的就是头插法添加节点的方式，将链表头指向栈顶，这样在出栈的时候就直接将链表头指向的数据pop出去，然后再将链表头（栈顶）向后移动，可以很方便的实现后进先出的操作。
二、链式栈数据结构
#define LIST_STACK_NUM(pstack) (pstack->num)
#define LIST_STACK_IS_EMPTY(pstack) (pstack->top == NULL)
struct list_stack_node
{
struct list_stack_node *next; /* next node*/
int value_size; /* value size */
void *value; /* node value */
};
struct list_stack
{
struct list_stack_node *top; /* stack top */
int num; /* stack node num */
};三、链式栈操作函数声明
extern struct list_stack* list_stack_creat(void);
extern int list_stack_init (struct list_stack *stack);
extern int list_stack_empty (struct list_stack *stack);
extern int list_stack_destory(struct list_stack *stack);
extern int list_stack_pop (struct list_stack *stack, void *out_data);
extern int list_stack_push(struct list_stack *stack, void *in_data, int dsize);
extern void list_stack_test(void);四、创建链式栈
1、栈头部动态创建
/**
* dynamically create a list stack.
*
* @return NULL:malloc fail
* !NULL:success
*/
struct list_stack* list_stack_creat(void)
{
struct list_stack *stack = NULL;
stack = LIST_STACK_CALLOC(1,sizeof(*stack));
if (stack == NULL)
return NULL;
stack->top = NULL;
stack->num = 0;
return stack;
}2、栈头部静态创建
/**
* init a list stack.
*
* @param stack:list stack
* @return -1:stack is null
* 0:success
*/
int list_stack_init(struct list_stack *stack)
{
if (stack == NULL)
return -1;
stack->top = NULL;
stack->num = 0;
return 0;
}五、出栈
/**
* pop data from the array stack.
*
* @param list_stack: array stack
* @return -1: fail
* -2: stack is empty
* 0: success
*/
int list_stack_pop (struct list_stack *stack, void *out_data)
{
struct list_stack_node *node = NULL;
if (stack == NULL)
return -1;
if (LIST_STACK_IS_EMPTY(stack))
return -2;
node = stack->top;
stack->top = node->next;
stack->num--;
memcpy(out_data, node->value, node->value_size);
LIST_STACK_FREE(node->value);
LIST_STACK_FREE(node);
node->value = NULL;
node = NULL;
return 0;
}六、入栈
/**
* push data to the list stack forward stack top.
*
* @param stack: list stack
* @param in_data: push data
* @return -1: fail
* 0: success
*/
int list_stack_push(struct list_stack *stack, void *in_data, int dsize)
{
struct list_stack_node *node = NULL;
if (stack == NULL)
return -1;
/* malloc node space */
node = LIST_STACK_MALLOC(sizeof(*node));
if (node == NULL)
return -1;
/* malloc value space */
node->value = LIST_STACK_MALLOC(dsize);
if (node->value == NULL)
return -1;
memcpy(node->value, in_data, dsize);
node->value_size = dsize;
node->next = stack->top;
stack->top = node;
stack->num++;
return 0;
}七、栈删除
/**
* delete list stack space.
*
* @param stack: list stack
* @return -1: fail
* 0:success
*/
int list_stack_empty(struct list_stack *stack)
{
struct list_stack_node *node = NULL;
if (stack == NULL)
return -1;
while (!LIST_STACK_IS_EMPTY(stack))
{
node = stack->top;
stack->top = node->next;
stack->num--;
LIST_STACK_FREE(node->value);
node->value = NULL;
LIST_STACK_FREE(node);
node = NULL;
}
return 0;
}八、栈销毁
/**
* delete and destroy a list stack.
*
* @param stack: list stack
* @return -1: fail
* 0:success
*/
int list_stack_destory(struct list_stack *stack)
{
if (list_stack_empty(stack) != 0)
return -1;
LIST_STACK_FREE(stack);
stack = NULL;
return 0;
}九、验证程序
struct list_stack *list_stack_head;
int list_stack_w[5] = {11,22,33,44,55};
int list_stack_r[5] = {0};
void list_stack_test(void)
{
list_stack_head = list_stack_creat();
list_stack_push(list_stack_head, (void*)&list_stack_w[0], 4);
list_stack_push(list_stack_head, (void*)&list_stack_w[1], 4);
list_stack_push(list_stack_head, (void*)&list_stack_w[2], 4);
list_stack_push(list_stack_head, (void*)&list_stack_w[3], 4);
list_stack_push(list_stack_head, (void*)&list_stack_w[4], 4);
list_stack_pop(list_stack_head, (void*)&list_stack_r[0]);
list_stack_pop(list_stack_head, (void*)&list_stack_r[1]);
list_stack_pop(list_stack_head, (void*)&list_stack_r[2]);
list_stack_pop(list_stack_head, (void*)&list_stack_r[3]);
list_stack_pop(list_stack_head, (void*)&list_stack_r[4]);
list_stack_push(list_stack_head, (void*)&list_stack_w[0], 4);
list_stack_pop(list_stack_head, (void*)&list_stack_r[0]);
list_stack_push(list_stack_head, (void*)&list_stack_w[1], 4);
list_stack_pop(list_stack_head, (void*)&list_stack_r[1]);
list_stack_push(list_stack_head, (void*)&list_stack_w[2], 4);
list_stack_pop(list_stack_head, (void*)&list_stack_r[2]);
list_stack_push(list_stack_head, (void*)&list_stack_w[3], 4);
list_stack_pop(list_stack_head, (void*)&list_stack_r[3]);
list_stack_push(list_stack_head, (void*)&list_stack_w[4], 4);
list_stack_pop(list_stack_head, (void*)&list_stack_r[4]);
}