sizeof运算符和memcpy的用法

#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
void test(int * a)
{
	cout<<sizeof(a)<<endl;
}
int main()
{
	char s1[]="hello";
	char s2[]="aaaaaaa";
	int a1[]={1,2,3,4,5};
	int a2[]={6,7};
	int n=strlen(s1);
	int m=sizeof(a2);
	char *s3,*s4;
	s3=s1;
	s4=s2;
	cout<<sizeof(s3)<<endl;
	memcpy(s2+1,s1,n);
	memcpy(a1+1,a2,m);
	for(int i=0;i<sizeof(a1)/4;i++)
	{
		cout<<a1[i]<<" ";
	}
	printf("\n%s\n",s2+1);
	printf("%s\n",s2+1);
	memcpy(s4,s3,n);
	printf("%s\n",s4+1);
	test(a1);
}