c++ new delete 分配二维数组

#include <iostream>

using namespace std;

int main(void)
{
        int **p;

        p = new int*[3];

        for (int i = 0; i < 3; i++)
                p[i] = new int[4];

        for (int i = 0; i < 3; i++) {
                for (int j = 0; j < 4; j++)
                        p[i][j] = i+j;
        }

        for (int i = 0; i < 3; i++)
                delete []p[i];

        delete []p;

        return 0;
}