reason why it doesn't works on visual 2019 - c++

Question

I don't think there's a problem with coding grammar or composition. I drew it with my hands and checked it several times and found no particular problem. And I've tried this many times.
I tried to repeat over and over, but it just shuts down immediately without any output on the run window when I use the visual studio 2019 version. I've been Googling several times, but I can't find the solution I want.
Have I reinstall the visual program or have to manipulate extra options?
plz give some solutions
#include<iostream>
using namespace std;
#include<stdlib.h>
class Node {
public:
int data;
Node * next;
};
class Stack {
public:
Node *top;
Stack() {
top->next = NULL;
}
void push(int data);
int pop();
void show();
};
void Stack::push(int data)
{
Node *node = new Node;
node->data = data;
if (top->next == NULL) {
node->next = NULL;
top->next = node;
}
else {
node->next = top->next;
top->next = node;
}
}
int Stack::pop()
{
if (top-> next == NULL) {
cout << "stack empty" << endl;
return 0;
}
Node *temp = new Node;
temp = top->next;
int data = temp->data;
top->next = temp->next;
delete temp;
return data;
}
void Stack::show() {
Node *cur = new Node;
cur = top-> next;
while (cur != NULL) {
cout << cur-> data << "->";
cur = cur-> next;
}
}
int main() {
Stack s;
s.push(5);
s.push(1);
s.push(3);
s.show();
cout << endl;
cout << s.pop() << endl;
s.show();
return 0;
}

Answer 1

In your constructor
Stack() {
top->next = NULL;
}
top has never been given a value, so top->next is an error.
Looks to me that most of your code would be fixed if you replaced top->next with top throughout.
There's another error here
void Stack::show() {
Node *cur = new Node;
cur = top-> next;
You assign cur to a new node and then you forget about that and assign it to something else on the very next line. Just do this
void Stack::show() {
Node *cur = top-> next;
(but top-> next should really just be top as explained above).
and the same error here
Node *temp = new Node;
temp = top->next;
why assign a new node to temp if on the very next line you assign something else to temp?
Here's your code will all the bugs fixed (I think)
class Stack {
public:
Node *top;
Stack() {
top = NULL;
}
void push(int data);
int pop();
void show();
};
void Stack::push(int data)
{
Node *node = new Node;
node->data = data;
node->next = top;
top = node;
}
int Stack::pop()
{
if (top == NULL) {
cout << "stack empty" << endl;
return 0;
}
Node *temp = top;
int data = temp->data;
top = temp->next;
delete temp;
return data;
}
void Stack::show() {
Node *cur = top;
while (cur != NULL) {
cout << cur-> data << "->";
cur = cur-> next;
}
}