数据结构之队列的链式结构基本操作-初始化-判断队列是否为空-入队-出队-获取队头元素

完整可运行代码：

#include <stdio.h>
#include <stdlib.h>typedef int ElemType;typedef struct QueueNode
{ElemType data;struct QueueNode *next;
}QueueNode;typedef struct 
{QueueNode *front;QueueNode *rear;
}Queue;//初始化
Queue* initQueue()
{Queue *q = (Queue*)malloc(sizeof(Queue));QueueNode *node = (QueueNode*)malloc(sizeof(QueueNode));node->data = 0;node->next = NULL;q->front = node;q->rear = node;return q;
}//判断队列是否为空为空
int isEmpty(Queue *q)
{if (q->front == q->rear){return 1;}else{return 0;}
}//入队
void equeue(Queue *q, ElemType e)
{QueueNode *node = (QueueNode*)malloc(sizeof(QueueNode));node->data = e;node->next = NULL;q->rear->next = node;q->rear = node;
}//出队
int dequeue(Queue *q, ElemType *e)
{if (isEmpty(q)){printf("空的\n");return 0;}QueueNode *node = q->front->next;*e = node->data;q->front->next = node->next;if (q->rear == node){q->rear = q->front;}free(node);return 1;
}//获取队头元素
ElemType getFront(Queue *q)
{if (isEmpty(q)){printf("空的\n");return 0;}return q->front->next->data;
}int main()
{Queue *q = initQueue();equeue(q, 10);equeue(q, 20);equeue(q, 30);equeue(q, 40);equeue(q, 50);ElemType e;dequeue(q, &e);printf("出队%d\n", e);dequeue(q, &e);printf("出队%d\n", e);printf("%d\n", getFront(q));return 0;
}

运行结果：