C语言环形队列

#include 
#define Len 6
unsigned char Input_Buff[6] = {0}; //用户输入缓冲区
unsigned char Input_Num  = 0;      //输入队列数据字节数
unsigned char Output_Num = 0;      //从队列取出的数据字节数
struct Queue
{
    unsigned char  Buffer[Len]; 
    unsigned char* Head;
    unsigned char* Tail;
};
Queue Ring_Queue;
void Empty() { //清空队列
    Ring_Queue.Head = Ring_Queue.Buffer;//Buffer缓冲区数组
    Ring_Queue.Tail = Ring_Queue.Buffer;
}

void Write(unsigned char* pData, unsigned char Data_Len) {  //入队列
    for (unsigned char Data_Num = 0; Data_Num < Data_Len; Data_Num++) {
        Ring_Queue.Buffer[Ring_Queue.Tail - Ring_Queue.Buffer] = *pData;
        pData++; 
        Ring_Queue.Tail++; //尾指针指向写入数据的末端
        if (Ring_Queue.Tail == Ring_Queue.Buffer + Len) {
            Ring_Queue.Tail = Ring_Queue.Buffer;
        }
        if (Ring_Queue.Head == Ring_Queue.Tail) { //不覆盖旧数据
            return;
        }
        printf("nr");
    }
}


void Read(unsigned char Read_Len) { //从队列中取出
    unsigned char Result = 0;
    for (unsigned char Read_Num = 0; Read_Num < Read_Len; Read_Num++) {
        Result = *(Ring_Queue.Head); //头指针指向读出数据后队列中剩余数据的开头
        *(Ring_Queue.Head) = NULL;
        printf("%hhunr", Result);
        Ring_Queue.Head++;
        if (Ring_Queue.Head == Ring_Queue.Buffer + Len) {
            Ring_Queue.Head = Ring_Queue.Buffer;
        }
    }
    printf("nr");
}
void Key_Input() {
    printf("输入数据：nr");
    for (unsigned char Scanf_Num = 0; Scanf_Num < 6; Scanf_Num++) {
        scanf_s(" %hhu", &Input_Buff[Scanf_Num]);  //注意%hhu前的空格
    }
    printf("输入长度：nr");
    scanf_s("%hhu", &Input_Num);
    printf("读取长度：nr");
    scanf_s("%hhu", &Output_Num);
}
int main() {
    Empty();
    while (1) {
        Key_Input();
        Write(Input_Buff, Input_Num);
        Read(Output_Num);
    }
    return 0;
}

验证效果 输入4个数字（这里必须输入六个数字后截取前四个，暂时没想到很好的解决办法），取出3个，再输入5个，全部取出，观察是否没有覆盖旧数据。

 可以看到第一次输入的1 2 3 4 ，取出的是1 2 3，此时队列中还剩4 ，写入 9 8 7 6 5 后，由于不覆盖旧数据，因此队列中应该是4 9 8 7 6 5，最终验证代码正确。