定義一個節點，裡面包含元素型別，指向下一個節點的指標。然後定義一個結構體，裡面兩個指標，指向隊頭和隊尾

typedef struct QNode {
  int data;
  struct QNode * next;
}QNode, * Queue;

typedef struct {
  Queue front;
  Queue rear;
}LinkQueue;

void EnQueue(LinkQueue * q, int x)
{
  Queue p = (Queue)malloc(sizeof(QNode));
  if (!p) {
    printf("無記憶體空間可分配\n");
  }

  p->data = x;
  p->next = NULL;
  q->rear->next = p;
  q->rear = p;
}
 

void DeQueue(LinkQueue * q)
{
  QNode * p;
  if (IsEmpty(&q)) {
    printf("空列\n");
  }

  p = q->front->next;
  q->front->next = p->next;
  if (q->rear == p) q->rear = q->front;
  free(p);
  printf("出隊成功\n");
}

輸出佇列元素，首先判斷是否為空。不要動隊頭和隊尾指標，否則你移動了了個指標就破壞了佇列結構，你將隊頭指標的地址告訴節點指標，讓節點進行遍歷，從而進行保護

void print(LinkQueue * q)
{
  QNode * p = q->front->next;

  if (IsEmpty(&q)) {
    printf("空隊\n");
  }
  while (p) {
    printf("%d ", p->data);
    p = p->next;
  }
  printf("\n\n");
}

具體實現如下

#include<stdio.h>
#include<stdlib.h>

typedef struct QNode {
  int data;
  struct QNode * next;
}QNode, * Queue;

typedef struct {
  Queue front;
  Queue rear;
}LinkQueue;

void InitialQueue(LinkQueue * q)
{
  q->front = q->rear = (Queue)malloc(sizeof(QNode));
  if (!q->front) {
    printf("無記憶體空間可分配\n");
  }
  q->front->next = NULL;
  printf("初始化成功\n");
}

void EnQueue(LinkQueue * q, int x)
{
  Queue p = (Queue)malloc(sizeof(QNode));
  if (!p) {
    printf("無記憶體空間可分配\n");
  }

  p->data = x;
  p->next = NULL;
  q->rear->next = p;
  q->rear = p;
}

int IsEmpty(LinkQueue * q)
{
  return (q->front== q->rear)?1:0;
}

void DeQueue(LinkQueue * q)
{
  QNode * p;
  if (IsEmpty(&q)) {
    printf("空列\n");
  }

  p = q->front->next;
  q->front->next = p->next;
  if (q->rear == p) q->rear = q->front;
  free(p);
  printf("出隊成功\n");
}

void DesQueue(LinkQueue * q)
{
  while (q->front) {
    q->rear = q->front->next;
    free(q->front);
    q->front = q->rear;
  }
  printf("銷燬成功\n");
  exit(1);
}

void print(LinkQueue * q)
{
  QNode * p = q->front->next;

  if (IsEmpty(&q)) {
    printf("空隊\n");
  }
  while (p) {
    printf("%d ", p->data);
    p = p->next;
  }
  printf("\n\n");
}

int main(void)
{
  LinkQueue queue;
  int num, flag;
  InitialQueue(&queue);

  while (scanf("%d", &num)) {
    EnQueue(&queue, num);
  }
  getchar();

  printf("1.入隊     2.出隊\n");
  printf("3.判斷隊是否為空     4.輸出佇列     5.銷燬佇列     6.退出\n");
  while (scanf("%d", &flag) && flag != 6) {
    switch (flag) {
      case 1: printf("輸入入隊元素:");scanf("%d", &num);EnQueue(&queue, num);break;
      case 2: DeQueue(&queue);break;
      case 3: printf("%s\n\n", IsEmpty(&queue)==1?"空隊":"非空隊");break;
      case 4: print(&queue);break;
      case 5: DesQueue(&queue);break;
      default: printf("請輸入合法操作!\n\n");break;
    }
    printf("1.入隊     2.出隊\n");
    printf("3.判斷隊是否為空     4.輸出佇列     5.銷燬佇列     6.退出\n");
  }

  return 0;
}