用栈操作实现队列的操作

struct Queue {
int data;
struct Queue* next;
};

typedef struct Queue Queue;

/* Create a queue */
void queueCreate(Queue *queue, int maxSize) {

queue = (Queue*)malloc(sizeof(Queue));
queue->next = NULL;
Queue* end_of_queue = queue;

while (maxSize--) {

int data_in_node;
Queue* q = (Queue*)malloc(sizeof(Queue));
if (NULL == q)
break;

printf("Please input the data of this node: ");
scanf("%d", &data_in_node);

q->next      = end_of_queue->next;
q->data      = data_in_node;
end_of_queue->next  = q;
end_of_queue = q;
}
}

/* Push element x to the back of queue */
void queuePush(Queue *queue, int element) {

Queue* q    =   (Queue*)malloc(sizeof(Queue));
if (NULL == q)
return ;
Queue* end  =   queue->next;

while (NULL != end->next)
end = end->next;

q->next     =   end->next;
end->next   =   q;
}

/* Removes the element from front of queue */
void queuePop(Queue *queue) {
if (NULL == queue->next)
return;

Queue* top  = queue->next;
queue->next = top->next;
free(top);
}

/* Get the front element */
int queuePeek(Queue *queue) {

if (NULL == queue->next)
return -1;
return (queue->next->data);
}

/* Return whether the queue is empty */
bool queueEmpty(Queue *queue) {

return (NULL == queue->next);
}

/* Destroy the queue */
void queueDestroy(Queue *queue) {

if (NULL == queue->next)
return ;

Queue* ds     = queue->next;
Queue* dsNext = ds->next;

while (NULL != dsNext->next) {

free(ds);
ds = dsNext;
dsNext = dsNext->next;
}

free(dsNext);
queue->next = NULL;
}