动态分配的标准写法（new, delete; malloc, free）

#include <iostream>
using namespace std;

int main(void)
{
int *p;
p = new int(1);					//	1
cout << *p << endl;

int *q;
q = (int *)malloc(sizeof(int));
*q = 1;
cout << *q << endl;

return 0;
}

#include <iostream>
using namespace std;

int main(void)
{
int *p = NULL;
p = new(nothrow) int(1);				//	1
if (p == NULL) {						//	2
cerr << "Allocate failed!" << endl;
exit(OVERFLOW);
}

cout << *p << endl;

delete p;								//	3
p = NULL;								//	4

/*----------------------------------------------------*/
int *q = NULL;
q = (int *)malloc(sizeof(int));			//	1
if (q == NULL) {						//	2
cerr << "Allocate failed!" << endl;
exit(OVERFLOW);
}

*q = 1;
cout << *q << endl;

free(q);								//	3
q = NULL;								//	4

return 0;
}