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

struct QueueRecord;
typedef struct QueueRecord* Queue;
typedef int ElementType;

#define MinElementSize 10

// 佇列的資料結構
struct QueueRecord
{
    int Capacity;
    int Front;
    int Rear;
    int Size;
    ElementType* Array;
};

// 設定佇列初始值
void MakeEmpty(Queue Q)
{
    Q->Size = 0
 
;
    Q->Front = 1;
    Q->Rear = 0;
}

//Queue Structure: Front<<<----<<<----Rear
Queue CreateQueue(int MaxElements)
{
    Queue Q;

    if(MaxElements < MinElementSize)
    {
        printf("queue size is too small\n");
        return NULL;
    }

    Q = malloc(sizeof(struct
 
 QueueRecord));
    if(Q == NULL)
    {
        printf("queue malloc failed\n");
        return NULL;
    }

    Q->Array = malloc(sizeof(ElementType)*MaxElements);
    if(Q->Array == NULL)
    {
        printf("Q->Array malloc failed\n");
        return NULL;
    }

    Q->Capacity = MaxElements;
    MakeEmpty(Q);
    return
 
 Q;
}

// 判斷佇列是否為空
int IsEmpty(Queue Q)
{
    return Q->Size == 0;
}

// 判斷佇列是否為滿
int IsFull(Queue Q)
{
    return Q->Size == Q->Capacity;
}

// 讓佇列的頭尾迴圈
int Succ(int value, Queue Q)
{
    value++;
    if(value == Q->Capacity)
        value = 0;
    return value;
}

// 入隊
void Enqueue(ElementType X, Queue Q)
{
    if(IsFull(Q))
    {
        printf("queue is full\n");
        return;
    }
    Q->Size++;
    Q->Rear = Succ(Q->Rear, Q);
    Q->Array[Q->Rear] = X;
}

// 出隊
void Dequeue(Queue Q)
{
    if(IsEmpty(Q))
    {
        printf("queue is empty.\n");
        return;
    }
    Q->Size--;
    Q->Front = Succ(Q->Front, Q);
}

// 取佇列頭元素，並出隊頭元素
ElementType FrontAndDequeue(Queue Q)
{
    if(IsFull(Q))
    {
        printf("queue is empty.\n");
        return 0;
    }
    Q->Size--;
    ElementType tmp = Q->Array[Q->Front];
    Q->Front = Succ(Q->Front, Q);
    return tmp;
}

void Free(Queue Q)
{
    free(Q->Array);
    free(Q);
}

void PrintQueue(Queue Q)
{
    for(int i=Q->Front; i<=Q->Rear; i++)
    {
        printf("pos: %d, %d\n",i,Q->Array[i]);
    }
}

int main()
{
    Queue Q = CreateQueue(10);
    for(int i=1;i<=3;i++)
    {
        Enqueue(i, Q);
    }
    PrintQueue(Q);

    printf("dequeue\n");
    for(int i=1;i<=3;i++)
    {
        printf("%d\n",FrontAndDequeue(Q));
    }

    // Dequeue(Q);
    PrintQueue(Q);
    return 0;
}