创建一个空循环用C语言实现，队列，实现入队、出队、返回队列长度、返回队列队头元素、遍历队列等基本算法。

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

#define MAX_SIZE 100

typedef struct {
    int data[MAX_SIZE];
    int front;
    int rear;
} Queue;

void initQueue(Queue *q) {
    q->front = q->rear = 0;
}

int isEmpty(Queue q) {
    return q.front == q.rear;
}

int isFull(Queue q) {
    return (q.rear + 1) % MAX_SIZE == q.front;
}

int enqueue(Queue *q, int item) {
    if (isFull(*q)) {
        return 0;
    }
    q->data[q->rear] = item;
    q->rear = (q->rear + 1) % MAX_SIZE;
    return 1;
}

int dequeue(Queue *q) {
    if (isEmpty(*q)) {
        return -1; // 队列为空
    }
    int item = q->data[q->front];
    q->front = (q->front + 1) % MAX_SIZE;
    return item;
}

int getFront(Queue q) {
    if (isEmpty(q)) {
        return -1; // 队列为空
    }
    return q.data[q.front];
}

int size(Queue q) {
    return (q.rear - q.front + MAX_SIZE) % MAX_SIZE;
}

void traverse(Queue q) {
    int i = q.front;
    while (i != q.rear) {
        printf("%d ", q.data[i]);
        i = (i + 1) % MAX_SIZE;
    }
    printf("\n");
}

int main() {
    Queue q;
    initQueue(&q);
    enqueue(&q, 1);
    enqueue(&q, 2);
    enqueue(&q, 3);
    printf("队列长度为%d\n", size(q));
    printf("队列队头元素为%d\n", getFront(q));
    printf("遍历队列：");
    traverse(q);
    dequeue(&q);
    printf("遍历队列：");
    traverse(q);
    return 0;
}