编写线性表（c++）

/*编写线性表并进行测试。数组的生成（动态内存分配）和初始化，常用操作*/

这个代码写的有问题，我想进行输入整数，但是无法进行 ，怎么改 ，在线等 谢谢！！

#include<iostream>
#include<iomanip>
using namespace std;
const int nmax = 100;
class Linelist
{
private:
int length;
int *arr;
public:
Linelist(void);
Linelist(int *t, int n);
Linelist(const Linelist &vt);//拷贝构造函数
~Linelist();
int isvalid(int n);//越界检查
void Bubblesort();//冒泡排序
friend ostream&operator<<(ostream&, const Linelist&);//输出
const Linelist&operator=(const Linelist&temp)//赋值运算符的重载
{
delete[]arr;
length = temp.length;
arr = new int[temp.length];
for (int i = 0; i < length; i++)
arr[i] = temp.arr[i];
return *this;
}
int& operator[](int elem);//下标运算符重载
};
Linelist::Linelist()
{
length = 0;
arr = NULL;
}
Linelist::Linelist(int *t, int n)
{
arr = new int[n];
length = n;
for (int i = 0; i < length; i++)
arr[i] = t[i];
}
Linelist::Linelist(const Linelist &vt)
{
this->length = vt.length;
this->arr = new int[this->length];
for (int i = 0; i < length; i++)
this->arr[i] = vt.arr[i];
}
Linelist::~Linelist()
{
delete[]arr;
}
int Linelist::isvalid(int n)
{
if (n <= nmax)
return true;
return false;
}
void Linelist::Bubblesort()
{
for (int i = 0; i < length - 1; i++)
for (int j = i + 1; j < length; j++)
if (this->arr[i] < this->arr[j])
{
int t;
t = this->arr[i];
this->arr[i] = this->arr[j];
this->arr[j] = t;
}
}
ostream& operator<<(ostream& os, const Linelist&t)
{
for (int i = 0; i < t.length; i++)
os << setw(5) << t.arr[i];
return os;
}
int &Linelist::operator[](int elem)
{
if (elem >= 0 && elem < length)
return *(arr + elem);
}
void main()
{
int a;
cout << "你想输入几个整数？" << '\t';
cin >> a;
int b[100];
int *p = &b;
cout << "请输入这些整数：" << endl;
for (int i = 0; i < a; i++)
cin >> *p;
system("pause");

}