#include<iostream> using namespace std;

#define MAXSIZE 20

typedef int ElemType;

typedef struct {     ElemType data[MAXSIZE];     int front; /* 頭指標 */     int rear; /* 尾指標，若佇列不空，指向佇列尾元素的下一個位置 */     int count; //元素個數 } SqQueue;

bool InitQueue(SqQueue &Sq) {     cout << "Init Queue ..." << endl;     Sq.front = 0;     Sq.rear = 0;     Sq.count = 0;     return true; }

bool ClearQueue(SqQueue &Sq) {     cout << "Clear Queue ..." << endl;     Sq.front = 0;     Sq.rear = 0;     Sq.count = 0;     return true; }

bool QueueEmpty(SqQueue &Sq) {     return Sq.count == 0; /* 佇列空的標誌 */ }

bool QueueFull(SqQueue &Sq) {     return Sq.count == MAXSIZE; }

int QueueLength(SqQueue &Sq) {     if (QueueFull(Sq))         return MAXSIZE;

    /* 佇列的當前長度 */     return (Sq.rear - Sq.front + MAXSIZE) % MAXSIZE; } /* 返回頭元素 */ bool GetHead(SqQueue &Sq, ElemType *pe) {     if (QueueEmpty(Sq))         return false;     else     {         *pe = Sq.data[Sq.front];         cout << "Get Head Item " << *pe << endl;         return true;     } }

bool EnQueue(SqQueue &Sq, ElemType Elem) {     /* 佇列滿 */     if (QueueLength(Sq) == MAXSIZE)         return false;     cout << "EnQueue Item " << Elem << endl;     Sq.data[Sq.rear] = Elem;/* 將元素賦值給隊尾 */     Sq.rear = (Sq.rear + 1) % MAXSIZE;/* rear指標向後移一位置， */     /* 若到最後則轉到陣列頭部 */     Sq.count++;     return true; }

bool DeQueue(SqQueue &Sq, ElemType *pe) {     if (QueueEmpty(Sq))         return false;     *pe = Sq.data[Sq.front];/* 將隊頭元素賦值給*pe */     cout << "DeQueue Item " << *pe << endl;     Sq.front = (Sq.front + 1) % MAXSIZE;/* front指標向後移一位置， */     /* 若到最後則轉到陣列頭部 */

    Sq.count--;     return true; }

bool QueueTraverse(SqQueue &Sq) {     if (QueueEmpty(Sq))     {         cout << "Queue is empty" << endl;         return false;     }

    cout << "Queue Traverse ..." << endl;     for (int i = 0;  i < Sq.count; i++)         cout << Sq.data[i + Sq.front] << ' ';     cout << endl;     return true; }

int main(void) {     SqQueue Sq;     InitQueue(Sq);     for (int i = 0; i < 20; i++)         EnQueue(Sq, i);     QueueTraverse(Sq);     if (!QueueEmpty(Sq))         cout << "Queue Length: " << QueueLength(Sq) << endl;     int result;     GetHead(Sq, &result);     DeQueue(Sq, &result);     DeQueue(Sq, &result);     if (!QueueEmpty(Sq))         cout << "Queue Length: " << QueueLength(Sq) << endl;     QueueTraverse(Sq);

    return 0; }