2）杨辉三角[1]队列实现

#include<iostream>
#include<iomanip>
using namespace std;

enum error{overflow,underflow,success};
const int maxlen=100;

class queue{
public:
    queue();
    bool empty()const;
    bool full()const;
    int get_front(int &x)const;
    error append(const int x);
    error serve();
private:
    int count;
    int rear,front;
    int data[maxlen];
};
queue::queue(){
    count=0;
    rear=front=0;
}

bool queue::empty()const{
    if(count==0)return true;
    return false;
}

bool queue::full()const{
    if(count==maxlen)return true;
    return false;
}

int queue::get_front(int &x)const{
    if(empty())return underflow;
    x=data[(front+1)%maxlen];
    return success;
}
error queue::append(const int x){
    if(full())return overflow;
    rear=(rear+1)%maxlen;
    data[rear]=x;
    count++;
    return success;
}

error queue::serve(){
    if(empty())return underflow;
    front=(front+1)%maxlen;
    count--;
    return success;
}

int main(){
    queue q;
    int n;
    cin>>n;
    int s1,s2;
    for(int i=1;i<n;i++)cout<<"  ";
    cout<<1<<endl;
    q.append(1);
    for(int i=2;i<=n;i++){
        s1=0;
        for(int k=1;k<=n-i;k++ )cout<<"  ";
        for(int j=1;j<=i-1;j++){
            q.get_front(s2);
            q.serve();
            cout<<s1+s2<<setw(4);
            q.append(s1+s2);
            s1=s2;
        }
        cout<<1<<endl;
        q.append(1);
    }
    return 0;

}