void *mm_malloc(size_t size)
{
    int newsize = ALIGN(size + SIZE_T_SIZE);
    void *p;

    if(findFree(newsize) == (void*) -1) // try to find available slot
        p = mem_sbrk(newsize); // increase heap cause not found
    else
        p = findFree(newsize);

    if (p == (void *)-1)
        return NULL;
    else{
        *(size_t *)p = size;
        PUT((void *)((char *)p + SIZE_T_SIZE),size);
        mm_check();
        return (void *)((char *)p + SIZE_T_SIZE);
        }

}

/*
 *Returns pointer to first available block
 */
void *findFree(size_t size){
    int *next = mem_heap_lo();
    while(!isFree(next) && GET_SIZE(next) > size && next > mem_heap_hi()){ // maybe should be == heap_hi
        next = NEXT_BLKP(next);
    }
    if(isFree(next)){
        return next; // return free
    }
    else{
        // no available spot
    }
    return (void*) -1;
}