静态顺序表的增删查改

#include<iostream>
using namespace std;
const int MAXSIZE = 100;
template<class T>
class Sqlist
{
public:
    Sqlist()
    {
        length = 0;
    }
    ~Sqlist()
    {
        length = 0;
    }
    void Insert(int i, int x);//指定位置插入
    void pushback(int x);//尾插
    void print();//遍历输出
    void deleteAll();//清空顺序表
    void popback();//尾删
    void erase(int i);//指定位置删除
    void find(int i);//用下标查找元素

private:
    int a[MAXSIZE];
    int length;//元素的有效长度
};
template<class T>
void Sqlist<T>::Insert(int i, int x)
{
    i--;
    if (i<0 || i>length)
        cout << "输入错误" << endl;
    else {int j;
        for (j = length; j > i; j--)
            a[j] = a[j - 1];
        a[i] = x;
        length++;
    }
}
template<class T>
void Sqlist<T>::pushback(int x)
{
    a[length] = x;
    length++;
}
template<class T>
void Sqlist<T>::print()
{
    if (length == 0)
        cout << "空表"<< endl;
    else
    {
        int i;
        for (i = 0; i < length; i++)
            cout << a[i] << ' ';
        cout <<"长度为 "<<length<< endl;
    }
}
template<class T>
void Sqlist<T>::deleteAll()
{
    length = 0;
}
template<class T>
void Sqlist<T>::popback()
{
    if (length == 0)
        cout << "空表" << endl;
    else
    length--;
}
template<class T>
void Sqlist<T>::erase(int i)
{
    i--;
    if (i<0 || i>length)
        cout << "输入错误" << endl;
    else {
        int j;
        for (j =i; j < length; j++)
            a[j] = a[j + 1];
        length--;
    }

}
template<class T>
void Sqlist<T>::find(int i)
{
    i--;
    if (i<0 || i>length)
        cout << "输入错误" << endl;
    else {
        cout << "要找的元素是 " <<a[i]<< endl;
    }

}
template<class T>
void Sqlist<T>::change(int i, int x)
{
    i--;
    if (i<0 || i>length)
        cout << "输入错误" << endl;
    else {
        a[i] = x;
        cout << "已修改 "<< endl;
    }

}
int main()
{
    Sqlist<int> l;
    l.pushback(1);
    l.pushback(1);
    l.Insert(3,4);
    l.Insert(2, 2);
    l.print();
    cout <<"l.find(3);" << endl;
    l.find(3);
    cout << "l.change(2,9);" << endl;
    l.change(2,9);
    l.print();
    cout << "l.erase(1);" << endl;
    l.erase(1);
    l.print();
    cout << "l.popback()" << endl;
    l.popback();
    l.print();
    cout << "l.deleteAll()" << endl;
    l.deleteAll();
    l.print();
    return 0;
}

结果如下