栈与队列的实现

目录

栈

初始化

销毁

入栈

出栈

获取栈顶元素

判断栈是否为空

栈的大小

---

队列

初始化

销毁

入队列

出队列

取队头

取队尾

判空

队列长度

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---

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栈

1.初始化

//初始化
void StackInit(ST*ps)
{
	ps->a = NULL;
	ps->capacity = 0;
	ps->top = 0;
}

2.销毁

void StackDestroy(ST*ps)
{
	free(ps->a);
	ps->a = NULL;
	ps->capacity = 0;
	ps->top = 0;
}

3.入栈

void StackPush(ST*ps, SDataType x)
{
	assert(ps);
	if (ps->top == ps->capacity)
	{
		int newcapacity = ps->capacity == 0 ? 4 : ps->capacity * 2;
		SDataType*tmp = (SDataType*)realloc(ps->a, newcapacity*(sizeof(SDataType)));
		assert(tmp);
		ps->a = tmp;
		ps->capacity = newcapacity;

	}
	ps->a[ps->top] = x;
	ps->top++;
}

4.出栈

void StackPop(ST*ps)
{
	assert(ps);
	assert(!StackEmpty(ps));
	ps->top--;
}

5.判空

bool StackEmpty(ST*ps)
{
	assert(ps);
	return ps->top == 0;
}

6.栈顶元素

SDataType StackFront(ST*ps)
{
	assert(ps);
	assert(!StackEmpty(ps));
	return ps->a[ps->top - 1];
}

7.栈大小

int StackSize(ST*ps)
{
	assert(ps);
	assert(!StackEmpty(ps));
	return ps->top;
}

---

队列

1.初始化

void QueueInit(Queue*pq)
{
	assert(pq);
	pq->head = pq->tail = NULL;

}

2.销毁

void QueueDestroy(Queue*pq)
{
	QNode*cur = pq->head;
	while (cur)
	{
		QNode*next = cur->next;
		free(cur);
		cur = next;
	}
	pq->head = pq->tail = NULL;
}

3.入队列

void QueuePush(Queue*pq, QDataType x)
{
	assert(pq);
	QNode*newnode = (QNode*)malloc(sizeof(QNode));
	assert(newnode);
	newnode->next = NULL;
	newnode->data = x;
	if (pq->head == NULL)
	{
		pq->head = pq->tail = newnode;
	}
	else
	{
		pq->tail->next = newnode;
		pq->tail = newnode;

	}
}

4.出队列

void QueuePop(Queue*pq)
{
	assert(pq);
	assert(!QueueEmpty(pq));
	if (pq->head->next == NULL)
	{
		free(pq->head);
		pq->head = pq->tail = NULL;
	}
	else
	{
		QNode*next = pq->head->next;
		free(pq->head);
		pq->head = next;
	}

}

5.判空

bool QueueEmpty(Queue*pq)
{

	assert(pq);
	return pq->head == NULL;

}

6.获取队头

QDataType QueueTop(Queue*pq)
{
	assert(pq);
	return pq->head->data;

}

7.获取队尾

//获取队尾
QDataType QueueBack(Queue*pq)
{
	return pq->tail->data;
}

8.队列长度

//队列长度
int QueueSize(Queue*pq)
{
	QNode*cur = pq->head;
	int size = 0;
	while (cur)
	{
		size++;
		cur = cur->next;

	}
	return size;

}