c++设计一个选择式菜单,1． 实现顺序循环或链式队列的进队列、出队列、判断队列空否、显示队列中全部元素的运算。

以下是使用顺序队列实现的选择式菜单代码：

#include <iostream>
using namespace std;

#define MAXSIZE 100  // 队列最大长度

typedef struct {
    int data[MAXSIZE];  // 队列数组
    int front;          // 队头指针
    int rear;           // 队尾指针
} SqQueue;

// 初始化队列
void InitQueue(SqQueue &q) {
    q.front = q.rear = 0;
}

// 判断队列是否为空
bool QueueEmpty(SqQueue q) {
    return q.front == q.rear;
}

// 判断队列是否已满
bool QueueFull(SqQueue q) {
    return (q.rear + 1) % MAXSIZE == q.front;
}

// 入队列
bool EnQueue(SqQueue &q, int x) {
    if (QueueFull(q)) {
        return false;
    }
    q.data[q.rear] = x;
    q.rear = (q.rear + 1) % MAXSIZE;
    return true;
}

// 出队列
bool DeQueue(SqQueue &q, int &x) {
    if (QueueEmpty(q)) {
        return false;
    }
    x = q.data[q.front];
    q.front = (q.front + 1) % MAXSIZE;
    return true;
}

// 显示队列中全部元素
void DisplayQueue(SqQueue q) {
    if (QueueEmpty(q)) {
        cout << "队列为空" << endl;
        return;
    }
    int i = q.front;
    while (i != q.rear) {
        cout << q.data[i] << " ";
        i = (i + 1) % MAXSIZE;
    }
    cout << endl;
}

int main() {
    SqQueue q;
    InitQueue(q);
    int choice, x;
    while (true) {
        cout << "1. 入队列" << endl;
        cout << "2. 出队列" << endl;
        cout << "3. 判断队列是否为空" << endl;
        cout << "4. 显示队列中全部元素" << endl;
        cout << "0. 退出" << endl;
        cout << "请输入选项: ";
        cin >> choice;
        switch (choice) {
            case 1:
                cout << "请输入要入队的元素: ";
                cin >> x;
                if (EnQueue(q, x)) {
                    cout << "入队成功" << endl;
                } else {
                    cout << "队列已满，入队失败" << endl;
                }
                break;
            case 2:
                if (DeQueue(q, x)) {
                    cout << "出队元素为: " << x << endl;
                } else {
                    cout << "队列为空，出队失败" << endl;
                }
                break;
            case 3:
                if (QueueEmpty(q)) {
                    cout << "队列为空" << endl;
                } else {
                    cout << "队列不为空" << endl;
                }
                break;
            case 4:
                DisplayQueue(q);
                break;
            case 0:
                return 0;
            default:
                cout << "无效选项，请重新输入" << endl;
                break;
        }
    }
    return 0;
}

使用链式队列实现的选择式菜单代码如下：

#include <iostream>
using namespace std;

typedef struct LNode {  // 链式队列结点结构体
    int data;
    struct LNode *next;
} LNode, *LinkQueuePtr;

typedef struct {         // 链式队列结构体
    LinkQueuePtr front;  // 队头指针
    LinkQueuePtr rear;   // 队尾指针
} LinkQueue;

// 初始化队列
void InitQueue(LinkQueue &q) {
    q.front = q.rear = new LNode;
    q.front->next = NULL;
}

// 判断队列是否为空
bool QueueEmpty(LinkQueue q) {
    return q.front == q.rear;
}

// 入队列
void EnQueue(LinkQueue &q, int x) {
    LinkQueuePtr p = new LNode;
    p->data = x;
    p->next = NULL;
    q.rear->next = p;
    q.rear = p;
}

// 出队列
bool DeQueue(LinkQueue &q, int &x) {
    if (QueueEmpty(q)) {
        return false;
    }
    LinkQueuePtr p = q.front->next;
    x = p->data;
    q.front->next = p->next;
    if (q.rear == p) {
        q.rear = q.front;
    }
    delete p;
    return true;
}

// 显示队列中全部元素
void DisplayQueue(LinkQueue q) {
    if (QueueEmpty(q)) {
        cout << "队列为空" << endl;
        return;
    }
    LinkQueuePtr p = q.front->next;
    while (p != NULL) {
        cout << p->data << " ";
        p = p->next;
    }
    cout << endl;
}

int main() {
    LinkQueue q;
    InitQueue(q);
    int choice, x;
    while (true) {
        cout << "1. 入队列" << endl;
        cout << "2. 出队列" << endl;
        cout << "3. 判断队列是否为空" << endl;
        cout << "4. 显示队列中全部元素" << endl;
        cout << "0. 退出" << endl;
        cout << "请输入选项: ";
        cin >> choice;
        switch (choice) {
            case 1:
                cout << "请输入要入队的元素: ";
                cin >> x;
                EnQueue(q, x);
                cout << "入队成功" << endl;
                break;
            case 2:
                if (DeQueue(q, x)) {
                    cout << "出队元素为: " << x << endl;
                } else {
                    cout << "队列为空，出队失败" << endl;
                }
                break;
            case 3:
                if (QueueEmpty(q)) {
                    cout << "队列为空" << endl;
                } else {
                    cout << "队列不为空" << endl;
                }
                break;
            case 4:
                DisplayQueue(q);
                break;
            case 0:
                return 0;
            default:
                cout << "无效选项，请重新输入" << endl;
                break;
        }
    }
    return 0;
}