#include "Memory.h"
#define NULL 0

typedef struct {
void *a;
void *next;
int size;
int isfree;
}Malloc;

struct Malloc *malloc_begin= (Malloc *) sbrk( sizeof(Malloc));
struct Malloc *New= (Malloc *) sbrk( sizeof(Malloc));
struct Malloc *b= (Malloc *) sbrk( sizeof(Malloc));



void* calloc(size_t nmemb, size_t size){
void *a=(void *)sbrk(size);
void *ptr;
ptr=a;
while( nmemb-1 !=0){
a=(void *)sbrk(size);
if(a==(void *)-1)
return NULL;

nmemb--;
}
return ptr;
}

void* malloc(size_t size){



if (malloc_begin->a==(void *) NULL)
{
New->a=(void *)sbrk(size);
New->a=size;
if (New->a==(void *)-1)
{
printf (" an error has occured") ;
return NULL;
}
malloc_begin->a=New->a;
}
else{
New=malloc_begin; 
while ( New->next && ( New->isfree==0 && New->size== size))
New=New->next; 
if( New->isfree==1 && New->size ==size){
New->isfree=0;
return New->a;
}

New->next=b;
b->a=(void *)sbrk(size);
b->size=size;
if (b->a==(void *)-1){
printf (" an error has occured") ;
return NULL;}
}
return b->a;
}

void free(void *ptr){

}


void *realloc(void *ptr, size_t size){
void *a;

if (ptr==0){
ptr=malloc(size);
if(ptr==NULL)
return NULL;}

else{
if (size==0)
free(ptr);
else {
a=malloc( sizeof(ptr)); 
if(a==NULL)
return NULL;
a=ptr;
free(ptr);
ptr=malloc(size);
if(ptr==NULL)
return NULL;
ptr=a;
}
}
return ptr;
}