为什么这是错？

/*
malloc / free            //c
new / delete            //c++
*/
#include<iostream>
using namespace std;
#include<cstdlib>

int main()
{
    /*
    int *p;
    p=new int;
    *p=10;
    cout<<hex<<*p<<endl;
    delete p;
    system("PAUSE");
    */
    /*
    int *ptr=new int[10];
    delete []ptr;
    */
    int *pi=new int[2][3][4];//??
    delete []pi;
    system("PAUSE");
    return 0;
}