二级指针作输入的三种内存模型

#include <iostream>
#include <string>
#include <windows.h>
using namespace std;

void main()
{
    int i, j;
    //指针数组
    char *a[] = { "123","456","789" };
    //二维数组
    char b[3][4] = { "123","456","789" };
    //malloc动态分配内存
    int **p = (int **)malloc(3 * sizeof(int *));
    for (i = 0; i < 3; i++)
    {
        p[i] = (int *)malloc(4 * sizeof(int));
        for (j = 0; j < 4; j++)
        {
            p[i][j] = i + j;
            cout << p[i][j] << endl;
        }
    }
    //释放内存
    for (i = 0; i < 3; i++)
    {
        free(p[i]);
    }
    free(p);
    system("pause");
}