#include <stdio.h>
#include <string.h>

int *p;

void *memory_alloc(unsigned int size)
{
	int x=1, zvysok;

	for(;;){
		if (p[0] >= size + 4){
			if(size % 4 != 0) {
				if (p[x] >= 0) {
					if (p[x]> size){
						p[x] = p[x] * (-1);
						p[0] = p[0] - ((p[x]*(-1)) + 4);
						return &p[x+1];
					}
					else if ((size > p[x]) && (p[x] != 0))
                      return NULL;
					else {
						zvysok = size % 4;
						p[x] = ((size +  (4-zvysok)) * (-1));
						p[0] = p[0] - (size +  (4-zvysok) + 4);
						return &p[x+1];
					}
				}
				else {
					if (p[x] < 0){
						x = x +1+ ((p[x]*(-1))/4);
					}
					else if (p[x] >= 0){
						x = x +1+ ((p[x])/4);
					}
				}
			}
			else{
				if (p[x] >= 0){
					if (p[x]> size) {
						p[x] = p[x] * (-1);
						p[0] = p[0] - ((p[x]*(-1)) + 4);
						return &p[x+1];
					}
                  else if ((size > p[x]) && (p[x] != 0))
                      return NULL;
					else {
						p[x] = ( size ) * (-1);
						p[0] -= (size + 4);
						return &p[x+1];
					}
				}
				else {
					if (p[x] < 0){
						x = x +1+ ((p[x]*(-1))/4);
					}
					else if (p[x] >= 0){
						x = x +1+ ((p[x])/4);
					}
				}
			}
		}
		else
			return NULL;
	}
}

int memory_free(void *valid_ptr)
{
	int x=2;
	int pom = 0;

	for(;;){
		if (&p[x] == valid_ptr){
			if(p[x-1] < 0) {
				p[x-1] = p[x-1] *(-1);
				p[0] = p[0] + p[x-1] +4;
				pom = 0;
				return 0;
			}
		}
		else {
			if (p[x-1] < 0) {
				x = x + 1 + ((p[x-1]*(-1))/4);

				pom = 0;
			}
			else {
				if (p[x-1] > 0) {
					x = x + 1 + ((p[x-1])/4);
					pom=0;
				}
			}
		}
		if (pom == 1){
			return 1;
		}
		pom = 1;
	}
}

int memory_check(void *ptr)
{


	return 0;
}

void memory_init(void *ptr, unsigned int size)
{
	p = ptr;
	p[0] = (size -4);
}