C언어 스택 구현 중... 힙과 데이터 메모리에 관련한 질문이 생겼습니다.

#include <stdio.h>
#include <stdlib.h>
 
#include <stdbool.h>
 
#define MAX_SIZE 100
 
typedef struct 
{
    int key;
    int data;
} element;
 
typedef struct 
{
    element* item;
    int top;
} Stack;
 
void CreateStack(Stack* sp)
{
    element ele[MAX_SIZE];       //<-------- 함수안에서 지역 변수를 사용한것이 문제 ★★★★★
 
    int i=0;
    for(i=0; i<100; i++)
    {
        ele[i].data = i+1000;
        ele[i].key = i+1000;
    }
 
    //함수 내부에 정적변수'는 함수 밖으로 나가면. 소멸 되거나.
    //남더라도. 변경이 될 수 있을겁니다.
    sp->item = ele;
    sp->top = -1;
    printf("CreateStack() ele %x\n", ele);
    printf("CreateStack() sp->item %x\n", sp->item);
    printf("CreateStack() sp->item->data %d\n", sp->item->data);
    printf("CreateStack() sp->item->key %d\n", sp->item->key);
}
 
bool Push(Stack* sp, element ele)
{
    if (sp->top == 100)
    {
        printf("error : stack is full");
        return false;
    }
    else
    {
        sp->top++;
        printf("Push() sp->item[sp->top].data %d\n", sp->item[sp->top].data);
        printf("Push() sp->item[sp->top].key %d\n", sp->item[sp->top].key);
 
        sp->item[sp->top].data = ele.data;
        sp->item[sp->top].key = ele.key;
        printf("Push() sp->top %d\n", sp->top);
        return true;
    }
    return true;
}
 
element Pop(Stack* sp)
{
    if (sp->top == -1)
    {
        printf("error : stack is empty\n");
    }
    else
    {
        printf("Pop() sp->top %d\n", sp->top);
        element temp;
        temp = sp->item[sp->top];
        sp->top--;
        return temp;
    }
}
 
bool IsFull(Stack* sp)
{
    if (sp->top == 100)
    {
        printf("Stack is full\n");
        return true;
    }
    else
    {
        printf("Stack is not full\n");
        return false;
    }
}
 
bool IsEmpty(Stack* sp)
{
    if (sp->top == -1)
    {
        printf("Stack is empty\n");
        return true;
    }
    else
    {
        printf("Stack is not empty\n");
        return false;
    }
}
 
void PrintStack(Stack* sp)
{
    for (int i = 0; i < sp->top; i++)
    {
        printf("%d %d\n", sp->item[i].key, sp->item[i].data);
    }
}
 
int main()
{
    element el1;
    el1.data = 10;
    el1.key = 1;
 
    element el2;
    el2.data = 20;
    el2.key = 2;
 
    element el3;
    el3.data = 30;
    el3.key = 3;
 
    element el4;
    el4.data = 40;
    el4.key = 4;
 
    Stack st1;
    Stack* stp;
    stp = &st1;
 
    CreateStack(stp);
    printf("main() stp->item %x\n", stp->item);
    printf("main() stp->top %d\n", stp->top);
 
    for (int i = 0; i < 10; i++)
    {
        printf("main() %d %d\n", stp->item[i].key, stp->item[i].data);
    }
 
    Push(stp, el1);
    Push(stp, el2);
    Push(stp, el3);
    Push(stp, el4);
    Push(stp, el1);
    Push(stp, el2);
 
    element tmp1 = Pop(stp);
 
    for (int i = 0; i < stp->top; i++)
    {
        printf("%d %d\n", stp->item[i].key, stp->item[i].data);
    }
 
    PrintStack(stp);
    IsFull(stp);
    IsEmpty(stp);
    return 0;
}
 
//idone 출력 결과
CreateStack() ele 1e954ae0
CreateStack() sp->item 1e954ae0
CreateStack() sp->item->data 1000
CreateStack() sp->item->key 1000
main() stp->item 1e954ae0
main() stp->top -1
main() 1000 1000
main() 1001 1001
main() 1002 1002
main() 1003 1003
main() 1004 1004
main() 1005 1005
main() 1006 1006
main() 1007 1007
main() 1008 1008
main() 1009 1009
Push() sp->item[sp->top].data 1000
Push() sp->item[sp->top].key 1000
Push() sp->top 0
Push() sp->item[sp->top].data 1001
Push() sp->item[sp->top].key 1001
Push() sp->top 1
Push() sp->item[sp->top].data 1002
Push() sp->item[sp->top].key 1002
Push() sp->top 2
Push() sp->item[sp->top].data 1003
Push() sp->item[sp->top].key 1003
Push() sp->top 3
Push() sp->item[sp->top].data 1004
Push() sp->item[sp->top].key 1004
Push() sp->top 4
Push() sp->item[sp->top].data 1005
Push() sp->item[sp->top].key 1005
Push() sp->top 5
Pop() sp->top 5
1 10
2 20
3 30
4 40
1 10
2 20
3 30
4 40
Stack is not full
Stack is not empty
 
//윈도우10 64비트 - Visual Studio 2017 Community 출력 결과
CreateStack() ele d8eff520
CreateStack() sp->item d8eff520
CreateStack() sp->item->data 1000
CreateStack() sp->item->key 1000
main() stp->item d8eff520
main() stp->top -1
main() 1000 1000
main() 1001 1001
main() 1002 1002
main() 1003 1003
main() 1004 1004
main() 1005 1005
main() 1006 1006
main() 1007 1007
main() 1008 1008
main() 1009 1009
Push() sp->item[sp->top].data 1000
Push() sp->item[sp->top].key 1426214296
Push() sp->top 0
Push() sp->item[sp->top].data 0
Push() sp->item[sp->top].key 0
Push() sp->top 1
Push() sp->item[sp->top].data 0
Push() sp->item[sp->top].key 0
Push() sp->top 2
Push() sp->item[sp->top].data 32767
Push() sp->item[sp->top].key 1425063638
Push() sp->top 3
Push() sp->item[sp->top].data 32767
Push() sp->item[sp->top].key 1426214296
Push() sp->top 4
Push() sp->item[sp->top].data 1005
Push() sp->item[sp->top].key 1005
Push() sp->top 5
Pop() sp->top 5
1426214296 32767
0 0
-2145599704 54275
1425063638 32767
1426214296 32767
0 0
-2145599704 54275
1425063638 32767
Stack is not full
Stack is not empty