libstack/stack.c

#include <stdio.h>
#include <stdlib.h>

typedef struct {
	void** data;
	int top_index;
	int capacity;
	int curr_size;
} Stack;

Stack* new_stack(int stack_size) {
	Stack* stack = malloc(sizeof(Stack));
	stack->capacity = stack_size;
	stack->data = malloc(stack_size);
	stack->top_index = 0;
	stack->curr_size = 0;
	return stack;
}

void push(Stack* stack,void* element) {
	if (stack->curr_size >= stack->capacity-1) {
		stack->data = realloc(stack->data, stack->capacity*2);
		stack->capacity *= 2;
	}
	*(stack->data + stack->top_index) = element;
	printf("Adding to index %d\n",stack->top_index);
	stack->top_index++;
	stack->curr_size++;
	return;
}

void* pop(Stack* stack) {
	stack->top_index--;
	void* to_return = *(stack->data + stack->top_index);
	*(stack->data + stack->top_index) = NULL;

	stack->curr_size--;

	return to_return;
}

void* peek(Stack* stack) {
	void* to_return = *(stack->data + stack->top_index - 1);
	return to_return;
}

int size(Stack* stack) {
	return (stack->curr_size);
}

void main() {
	Stack* stack = new_stack(10);
	int a = 2;
	int b = 3;
	int c = 4;
	push(stack,(void *)&a);
	push(stack,(void *)&b);
	push(stack,(void *)&c);
	printf("%d\n",*( (int *) pop(stack)));
	printf("%d\n",*( (int *) pop(stack)));
	printf("%d\n",*( (int *) pop(stack)));
//	printf("%d\n",size(stack));
}