queue顺序C++

#include <iostream>
using namespace std;

class queue{
public:
    queue(unsigned int n):m_start(new int[n+1]),m_head(0),m_tail(0),m_capacity(n+1){}
    ~queue(){delete[] m_start;}
    void push(int e);
    void pop();
    int  front();
    int  back();
    bool isEmpty();
    bool isFull();
    int  size();    
private:
    int* m_start;
    int m_head;
    int m_tail; 
    int m_capacity;
};

void queue::push(int e){
    if((m_tail+1) % m_capacity != m_head){
        m_start[m_tail] = e;
        m_tail = (m_tail+1) % m_capacity;
    }else{
        cout << "queue is full.\n";
    }
}

void queue::pop(){
    if(m_tail == m_head){
        cout << "queue is empty.\n";
    }else{
        m_head = (m_head+1)%m_capacity;
    }
}

int  queue::front(){
    if(m_tail == m_head){
        cout << "queue is empty.\n";
        exit(1);
    }else{
        return m_start[m_head];
    }
}

int  queue::back(){
    if(m_tail == m_head){
        cout << "queue is empty.\n";
        exit(1);
    }else{
        return m_start[(m_tail-1+m_capacity)%m_capacity];
    }
}
bool queue::isEmpty(){
    return m_tail == m_head;
}
bool queue::isFull(){
    return m_head == (m_tail+1)%m_capacity;
}

int  queue::size(){
    if(m_head <= m_tail){
        return m_tail - m_head;
    }else{
        return m_tail - m_head + m_capacity;
    }
}

int main(){
    queue q(10);
    for(int i = 0 ; i < 10 ; ++i){
        q.push(i);
    }
    cout << "queue is full:  " <<  q.isFull() << endl;
    cout << "queue first is: " << q.front() << endl;
    cout << "queue last is:  " << q.back() << endl;

     for(int i = 0 ; i < 10 ; ++i){
        cout << "queue first is: " << q.front() << ends << "queue size is:  " << q.size() << endl;
        q.pop();
    }
    cout << "queue is empty: " << q.isEmpty() << endl;
    return 0;
}