Extract Previous Block's Allocation Status from Encoded Block Header

Task

Implement the function get_prev_status

• Write a function that takes a pointer to a block_header struct
• The block_header struct contains a single size_t field called size_status, which encodes the block size and status bits
• The second lowest bit (bit 1) of the size_status field indicates whether the previous block is allocated (1) or free (0)
• Your function should return 1 if the previous block is allocated or 0 if it is free

Function Signature

// Given a pointer to a block_header, return 1 if the previous block is allocated, 0 if it is free.
int get_prev_status(struct block_header* header);

---

Example

Encoded size_status value	Prev Allocated? (Output)
0x0000000000000040	0
0x0000000000000042	1
0x0000000000000041	0
0x0000000000000043	1
0x0000000000000100	0
0x0000000000000102	1
0x0000000000000101	0
0x0000000000000103	1
0x0000000000000200	0
0x0000000000000202	1
0x0000000000000201	0
0x0000000000000203	1
0x0000000000001000	0
0x0000000000001002	1
0x0000000000001001	0
0x0000000000001003	1

---

Code

#include <stddef.h>
 
struct block_header {
    size_t size_status;
};
 
size_t get_prev_status(struct block_header* block) {
    size_t dif = block->size_status >> 1;
    if (dif % 2 == 1) return 1;
    return 0;
}