一维和二维数组 动态内存分配

#include "stdafx.h"
#include <iostream> 
using namespace std;

int main() 
{ 
    int length,i; 
    int *p; 
    cin>>length; 
    p=new int[length]; 
    for(i=0;i<length;i++) 
    { 
        p[i]=i;     //不要写成*p[i]=i; 
        cout<<p[i]<<endl;   //不要写成cout<<*p[i]<<endl; 
    } 
    delete []p;
    p=0;
    return 0; 
}

int **p;

.....

    p = new int*[n];  //申请行空间
for (i=0;i<n;i++)
{
    p[i]=new int [n]; //申请列空间
}

#include "stdafx.h"
#include <iostream>
using namespace std;
int main()
{
    int (*p)[2]=new int[2][2];
    int i,j;
    int a[2][2]={1,2,3,4};
    for (i=0;i<2;i++)
        for (j=0;j<2;j++)
        {
            p[i][j]=a[i][j];
        }
        //p=a;
        cout<<"p[0][0]的地址为："<<p[0]<<endl<<endl;
        for (i=0;i<2;i++)
        {
            for (j=0;j<2;j++)
                cout<<p[i][j]<<"\t";
            cout<<endl;
        }
        delete[] p;
        p=0;
        return 0;
}