c++定義未知元素個數的二維數組

#include<iostream>
using namespace std;
int main()
{
    int x;
    int y;
    cout << "請輸入行數和列數" << endl;
    cout << "行數為：";
    cin >> x;
    cout << endl;
    cout << "列數為：";
    cin >> y;
    cout << endl;
    int** p;
    p = new int* [x];
    for (int i = 0; i < x; i++)
    {
        p[i] = new int[y];
        for (int k = 0; k < y; k++)
        {
            cout << "第" << i + 1 << "行" << "第" << k + 1 << "列數為；";
            cin >> p[i][k];
            cout << endl;
        }
    }
    for(int i=0;i<x;i++)
    {
        for (int k = 0; k < y; k++)
        {
            cout << p[i][k] << '\t';
        }
        cout << endl;
    }
    return 0;
}