c언어 간단한 스택 malloc 후 free 문제..

#include <stdio.h>
#include <stdlib.h>
 
#define MAX_STACK 10
typedef struct Stack{
	int top;
	char* stack;
}stack_t;
void push(stack_t* stack, char input, int stackOfSize);
char pop(stack_t* stack);
void init(stack_t* stack);
int main(void)
{
	int sizeOfStack;
	stack_t* stack1 = (stack_t*)malloc(sizeof(stack_t));
	while (1) { // 제대로 입력 받을 때까지 반복
		scanf("%d", &sizeOfStack);
		if (sizeOfStack >= 0 && sizeOfStack <= MAX_STACK) {
			break;
		}
		else if (sizeOfStack < 0) {
			printf("0 이상의 자연수를 입력해주세요\n");
		}
		else if (sizeOfStack > 10) {
			printf("10 이하의 자연수를 입력해주세요\n");
		}
		else if (sizeOfStack == 0) {
			exit(0);
		}
	}
	stack1->stack = (char*)malloc(sizeof(char) * sizeOfStack);
	init(stack1);
	push(stack1, 'l', sizeOfStack);
	push(stack1, 'b', sizeOfStack);
	pop(stack1);
 
	free(stack1->stack);
	free(stack1);
 
 
}
void push(stack_t* stackstruct, char input, int sizeOfStack)
{
	if (stackstruct->top >= sizeOfStack) {
		for (int i = stackstruct->top; i >= 1; i--) {
			char temp;
			temp = stackstruct->stack[i-1];
			stackstruct->stack[i-1] = stackstruct->stack[i];
		}
		stackstruct->stack[stackstruct->top] = input;
	}
	else {
		stackstruct->stack[stackstruct->top++] = input;
	}
}
char pop(stack_t* stackstruct)
{
	if (stackstruct->top == 0) {
		printf("Empty Stack can't pop anymore");
		return 'N'; // command meaning nothing
	}
	else {
		return stackstruct->stack[stackstruct->top--];
	}
}
void init(stack_t* stackstruck)
{
	stackstruck->top = 0;
}

#include <stdio.h>
#include <stdlib.h>
 
#define MAX_STACK 10
typedef struct Stack{
	int top;
	char* stack;
}stack_t;
void push(stack_t* stack, char input, int stackOfSize);
char pop(stack_t* stack);
void init(stack_t* stack);
int main(void)
{
	int sizeOfStack;
	stack_t* stack1 = (stack_t*)malloc(sizeof(stack_t));
 
	while (1) {
		scanf("%d", &sizeOfStack);
		if (sizeOfStack > 0 && sizeOfStack <= MAX_STACK) {
			stack1->stack = (char*)malloc(sizeof(char) * sizeOfStack);
			init(stack1);
			push(stack1, 'A', sizeOfStack);
			push(stack1, 'B', sizeOfStack);
			push(stack1, 'C', sizeOfStack);
			push(stack1, 'D', sizeOfStack);
			push(stack1, 'E', sizeOfStack);
			push(stack1, 'F', sizeOfStack);
			push(stack1, 'G', sizeOfStack);
			push(stack1, 'H', sizeOfStack);
			push(stack1, 'I', sizeOfStack);
			push(stack1, 'J', sizeOfStack);
			push(stack1, 'K', sizeOfStack);
 
			for (int i = 0; i < sizeOfStack; i++) {
				printf("%c", pop(stack1));
			}
			printf("\n");
			free(stack1->stack);
		}
		else if (sizeOfStack < 0) {
			printf("0 이상의 자연수를 입력해주세요\n");
		}
		else if (sizeOfStack > MAX_STACK) {
			printf("10 이하의 자연수를 입력해주세요\n");
		}
		else if (sizeOfStack == 0) {
			printf("Bye!\n");
			break;
		}
	}
	free(stack1);
}
void push(stack_t* stackstruct, char input, int sizeOfStack)
{
	if (stackstruct->top >= sizeOfStack) {
		stackstruct->top--;
		for (int i = 0; i < sizeOfStack - 1; i++) {
			stackstruct->stack[i] = stackstruct->stack[i + 1];
		}
		stackstruct->stack[stackstruct->top++] = input;
	}
	else {
		stackstruct->stack[stackstruct->top++] = input;
	}
}
char pop(stack_t* stackstruct)
{
	if (stackstruct->top == 0) {
		printf("Empty Stack can't pop anymore");
		return 'N'; // command meaning nothing
	}
	else {
		stackstruct->top--;
		return stackstruct->stack[stackstruct->top];
	}
}
void init(stack_t* stackstruck)
{
	stackstruck->top = 0;
}