ADT stack

#include<iostream>
using namespace std;
 
struct Stack
{
    int size;
    int top;
    int* s;
};
 
void create(Stack* st)
{
    cout << "enter size";
    cin >> st->size;
    st->top = -1;
    st->s = new int[st->size];
 
}
void Display(Stack st)
{
    for (int i = st.top; i>=0; i--)
    {
        cout << st.s[i]<< " ";
    }
}
 
void Push(Stack* St, int x)
{
    if (St->top == St->size - 1)
        cout << "overflow";
    else
    {
        St->top++;
        St->s[St->top] = x;
    }
}
 
int pop(Stack* st)
{
    int x = -1;
    if (st->top == -1)
        cout <<"";
    else
    {
        x = st->s[st->top--];
    }
    return x;
}
 
int peek(Stack st, int index)
{
    int x = -1;
    if (st.top - index + 1 < 0)
        cout << "z";
    x = st.s[st.top - index + 1];
 
    return x;
}
 
int Empty(Stack st)
{
    if (st.top == -1)
        return 1;
    return 0;
}
 
int isfuul(Stack st)
{
    return st.top == st.size - 1;
}
 
int stackTop(Stack st)
{
    if (!Empty(st))
        return st.s[st.top];
    return -1;
}
int main()
{
    Stack st;
    create(&st);
 
    Push(&st,1);
    Push(&st, 2);
    Push(&st, 3);
    pop(&st);
    //Display(st);
 
    cout << peek(st, 3);
 
 
    return 0;
}