hadoop 大数据环境配置 ssh免密登录 centos配置免密登录 hadoop(四)

思路 

实现 

完整代码附上：

typedef int QDataType;
typedef struct QueueNode
{
	QDataType data;
	struct QueueNode* next;
}QNode;

typedef struct Queue
{
	QNode* phead;
	QNode* ptail;
	int size;
}Queue;

//初始化
void QueueInit(Queue* pq);
//销毁
void QueueDestroy(Queue* pq);
//入队
void QueuePush(Queue* pq, QDataType x);
//出队
void QueuePop(Queue* pq);
//获取队头元素
QDataType QueueFront(Queue* pq);
//获取队尾元素
QDataType QueueBack(Queue* pq);
//检测队列中有效元素个数
int QueueSize(Queue* pq);
//检测队列是否为空
bool QueueEmpty(Queue* pq);

void QueueInit(Queue* pq)
{
	assert(pq);

	pq->phead = NULL;
	pq->ptail = NULL;
	pq->size = 0;
}

void QueueDestroy(Queue* pq)
{
	assert(pq);

	QNode* cur = pq->phead;
	while (cur)
	{
		QNode* next = cur->next;
		free(cur);
		cur = next;
	}

	pq->phead = pq->ptail = NULL;
	pq->size = 0;
}

void QueuePush(Queue* pq, QDataType x)
{
	assert(pq);

	QNode* newnode = (QNode*)malloc(sizeof(QNode));
	if (newnode == NULL)
	{
		perror("malloc fail");
		return;
	}
	newnode->data = x;
	newnode->next = NULL;

	if (pq->ptail == NULL)
	{
		assert(pq->phead == NULL);
		pq->phead = pq->ptail = newnode;
	}
	else
	{
		pq->ptail->next = newnode;
		pq->ptail = newnode;
	}

	pq->size++;
}

void QueuePop(Queue* pq)
{
	assert(pq);
	assert(!QueueEmpty(pq));

	if (pq->phead->next == NULL)
	{
		free(pq->phead);
		pq->phead = pq->ptail = NULL;
	}
	else
	{
		QNode* next = pq->phead->next;
		free(pq->phead);
		pq->phead = next;
	}

	pq->size--;
}

QDataType QueueFront(Queue* pq)
{
	assert(pq);

	return pq->phead->data;
}

QDataType QueueBack(Queue* pq)
{
	assert(pq);

	return pq->ptail->data;
}

int QueueSize(Queue* pq)
{
	assert(pq);

	return pq->size;
}

bool QueueEmpty(Queue* pq)
{
	assert(pq);

	return pq->size == 0;
}

typedef struct {
    Queue q1;
    Queue q2;
} MyStack;


MyStack* myStackCreate() {
    MyStack* obj = (MyStack*)malloc(sizeof(MyStack));
    if (obj == NULL)
    {
        perror("malloc fail");
        return NULL;
    }

    QueueInit(&obj->q1);
    QueueInit(&obj->q2);

    return obj;
}

void myStackPush(MyStack* obj, int x) {
    if (!QueueEmpty(&obj->q1))
    {
        QueuePush(&obj->q1, x);
    }
    else
    {
        QueuePush(&obj->q2, x);
    }
}

int myStackPop(MyStack* obj) {
    Queue* pEmptyQ = &obj->q1;
    Queue* pNonEmptyQ = &obj->q2;
    if (!QueueEmpty(&obj->q1))
    {
        pEmptyQ = &obj->q2;
        pNonEmptyQ = &obj->q1;
    }

    while (QueueSize(pNonEmptyQ) > 1)
    {
        QueuePush(pEmptyQ, QueueFront(pNonEmptyQ));
        QueuePop(pNonEmptyQ);
    }

    int top = QueueFront(pNonEmptyQ);
    QueuePop(pNonEmptyQ);

    return top;
}

int myStackTop(MyStack* obj) {
    Queue* pEmptyQ = &obj->q1;
    Queue* pNonEmptyQ = &obj->q2;
    if (!QueueEmpty(&obj->q1))
    {
        pEmptyQ = &obj->q2;
        pNonEmptyQ = &obj->q1;
    }

    int top = QueueBack(pNonEmptyQ);
    return top;
}

bool myStackEmpty(MyStack* obj) {
    return QueueEmpty(&obj->q1)
    && QueueEmpty(&obj->q2);
}

void myStackFree(MyStack* obj) {
    QueueDestroy(&obj->q1);
    QueueDestroy(&obj->q2);
    free(obj);
}

/**
 * Your MyStack struct will be instantiated and called as such:
 * MyStack* obj = myStackCreate();
 * myStackPush(obj, x);
 
 * int param_2 = myStackPop(obj);
 
 * int param_3 = myStackTop(obj);
 
 * bool param_4 = myStackEmpty(obj);
 
 * myStackFree(obj);
*/