C C++ คิววงกลม : Circular Queue

คิววงกลม : Circular Queue

เป็นการออกแบบมาเพื่อใช้ในการแก้ปัญหาในกรณีที่ยังมีพื้นที่เหลือในการเก็บข้อมูล คือคิวที่เปรียบเสมือนกับ ลิเนียร์อาเรย์ แตกต่างเพียงแต่ว่า คิววงกลมสามารถกลับไปใช้คิวหน้าได้ในกรณีที่หมดคิวปกติแล้ว

ขอส่งงานที่สามนะครับ

การเพิ่มข้อมูลเข้าไปในคิว Enqueue

void enq(myQueue* q, int data){
    if ((q->rear == MAXQUEUE -1 && q->front == 0 ) || q->rear +1 == q->front) {
        std::cout << "\nQueue if full" << std::endl;
        return;
    }
    if (q->rear== MAXQUEUE -1) {
        q->rear = 0;
        q->arr[q->rear] = data;
    } else {
        q->rear++;
        q->arr[q->rear] = data;
        if (q->front == -1) {
            q->front = 0;
        }
    }
}

การนำข้อมูลออกจากคิว Dequeue

void deq(myQueue* q) {
    if (q->front == -1 ) {
        std::cout << "Q is empty" <<std::endl;
        return ;
    }
    if (q->front == q->rear) {
        q->front = -1;
        q->rear = -1;
    return;
    }
    if (q->front == MAXQUEUE -1) {
        q->arr[q->front] =NULL;
        q->front =0;
        return;
    }
    q->arr[q->front] =NULL;
    q->front ++;
    return;
}

การแสดงผลข้อมูล display

void dp(myQueue* q) {
    std::cout << "\nDisplay Q" << std::endl;
    std::cout << "Rear -> " << q->rear  <<" Front -> "<< q->front << std::endl;

    if(q->front<= q->rear) {
        for(int i = 0; i <= q->rear ; i++) {
            std::cout << "["<< i+1 << "] "<< " -> " << q->arr[i] << ", ";
        }
        std::cout << "\n\n";
        return;
    }

    for(int i = q->front; i != q->rear ; i =((i+1)%MAXQUEUE)) {
        std::cout << "["<< i+1 << "] "<< " -> " << q->arr[i] << ", ";
    }
    std::cout << "["<< q->rear+1 << "] "<< " -> " << q->arr[q->rear] << ", ";
    std::cout << "\n\n";
    return;
}

code สำเร็จรูป

#include <iostream>
const int MAXQUEUE = 5;
struct myQueue {
    int arr[5];
    int rear = -1;
    int front = -1;
};

void enq(myQueue* q, int data);
void deq(myQueue* q);
void dp(myQueue* q) ;

int main() {
    myQueue myQ ;

    int menu;
    char ans = 'y';
    while (ans == 'y' || ans == 'Y') {
        std::cout << "Matee Suttapak \n " ;

        std::cout << "Pls select menu [1]:EnQueue [2]:Dequeue [3]:Show data " ;
        std::cin >> menu ;
        switch (menu) {
            case 1 :
                int data;
                std::cout << "\nInsert data : " ;
                std::cin>>data;
                enq(&myQ,data);
                break;
            case 2:
                deq(&myQ);
                break;
            case 3:
                dp(&myQ);
                std::cout << "Do you want to continue press \'Y\' to continue press another to Exit programs : ";
                std::cin >> ans ;
                continue;
            default:
                std::cout << "Pls select 1 -> 2";
                break;
        }

        std::cout << "\ndisplay Q" << std::endl;
        if (myQ.rear == -1) {
            std::cout << "\nQ is Empty." << std::endl;
        }
        dp(&myQ);
        std::cout << "\n\n";

//        std::cout << "Do you want to continue press \'Y\' to continue press another to Exit programs : ";
//        std::cin >> ans ;
    }
    return 0;
}

void enq(myQueue* q, int data){
    if ((q->rear == MAXQUEUE -1 && q->front == 0 ) || q->rear +1 == q->front) {
        std::cout << "\nQueue if full" << std::endl;
        return;
    }
    if (q->rear== MAXQUEUE -1) {
        q->rear = 0;
        q->arr[q->rear] = data;
    } else {
        q->rear++;
        q->arr[q->rear] = data;
        if (q->front == -1) {
            q->front = 0;
        }
    }
}

void deq(myQueue* q) {
    if (q->front == -1 ) {
        std::cout << "Q is empty" <<std::endl;
        return ;
    }
    if (q->front == q->rear) {
        q->front = -1;
        q->rear = -1;
    return;
    }
    if (q->front == MAXQUEUE -1) {
        q->arr[q->front] =NULL;
        q->front =0;
        return;
    }
    q->arr[q->front] =NULL;
    q->front ++;
    return;
}

void dp(myQueue* q) {
    std::cout << "\nDisplay Q" << std::endl;
    std::cout << "Rear -> " << q->rear  <<" Front -> "<< q->front << std::endl;

    if(q->front<= q->rear) {
        for(int i = 0; i <= q->rear ; i++) {
            std::cout << "["<< i+1 << "] "<< " -> " << q->arr[i] << ", ";
        }
        std::cout << "\n\n";
        return;
    }

    for(int i = q->front; i != q->rear ; i =((i+1)%MAXQUEUE)) {
        std::cout << "["<< i+1 << "] "<< " -> " << q->arr[i] << ", ";
    }
    std::cout << "["<< q->rear+1 << "] "<< " -> " << q->arr[q->rear] << ", ";
    std::cout << "\n\n";
    return;
}