请问各位神犇这份代码应该是21行错了，最后一个printf输不出结果

#include<cstdio>
using namespace std;
int main(){
	int tmp;
	scanf("%d",&tmp);
	printf("&tmp=%d\n",&tmp);
	int* p;
	p=new int();
	*p=tmp;
	printf("*p=%d p=%d\n",*p,p);
	int *q,*x;
	q=&tmp;
	*q=123;
	x=&tmp;
	printf("*q=%d q=%d x=%d *x=%d\n",*q,q,x,*x);
	*p=*q;
	printf("*p=%d p=%d *q=%d q=%d\n",*p,p,*q,q);
	*q=12345;
	p=q;
	printf("*p=%d p=%d *q=%d q=%d\n",*p,p,*q,q);	
	int **y;
	*y=p;
	printf("*y=%d **y=%d\n",*y,**y);
	return 0;
}