C语言实现链队列代码

#include <stdio.h>/* 队列的结构体 */typedef int DataType;#define NODE_LEN sizeof(NODE) /* 队列的节点 */typedef struct stNode{  DataType data;  struct stNode* next;}NODE;/* 队列 */typedef struct stQueue{  NODE* head; //队列的头  NODE* tail; //队列的尾}QUEUE;/* 初始化队列,不带头结点*/int initQueue(QUEUE* INQueue){  INQueue->head = NULL;  INQueue->tail = NULL;  return 0;}/* 从队尾插入一个元素 */int enQueue(QUEUE* InQueue,DataType InData){  NODE* pNewNode = (NODE*)malloc(NODE_LEN);  if (pNewNode == NULL)  {    return -1;  }  pNewNode->data = InData;  pNewNode->next = NULL;  /* 判断，现在队列里面有没有节点 */  if (InQueue->head == NULL)  {    InQueue->head = pNewNode;    InQueue->tail = pNewNode;  }  else  {    InQueue->tail->next = pNewNode;    InQueue->tail = pNewNode;  }  return 0;}/* 遍历该队列 */int visitQueue(QUEUE InQueue){  QUEUE* pstTemp = &InQueue;  /* 判断队列是否为空队列 */  if (pstTemp->head == NULL)  {    printf("visitQueue: this queue is empty/n");    return -1;  }  /* 遍历该队列中的所有元素 */  while (pstTemp->head->next != NULL)  {    printf("%d ", pstTemp->head->data);    pstTemp->head = pstTemp->head->next;  }  printf("%d /n", pstTemp->head->data);  return 0;}/* 出队列 */int delQueue(QUEUE* InQueue,DataType* OutData){  if (InQueue->head == NULL)  {    printf("delQueue: this queue is empty/n");    return -1;  }  *OutData = InQueue->head->data;  NODE* pstTemp = InQueue->head;  InQueue->head = InQueue->head->next;  delete pstTemp;  return 0;}/* 判断队列是否是空队列 */int isEmptyQueue(QUEUE InQueue){  if (InQueue.head == NULL)  {    return 0; //是空队列  }  return 1; //不是空队列}int main(){  /* 创建一个队列 */  QUEUE queue;  DataType data;  initQueue(&queue);  /* 入队列 */  enQueue(&queue, 12);  enQueue(&queue, 11);  enQueue(&queue, 2);  visitQueue(queue);  /* 出队列 */  delQueue(&queue, &data);  visitQueue(queue);  printf("data = %d/n", data);  visitQueue(queue);  if (0 == isEmptyQueue(queue))  {    printf("This is empty queue/n");  }  else  {    printf("This is not empty queue/n");  }  return 0;}