fixed math issue and some minor issues renamed custom free function

main.c

@@ -31,10 +31,16 @@ struct block *extend_heap(size_t s)
 
     struct block *b = (struct block *)sbrk(0); // Get the current break
 
-    if (sbrk(BLOCK_SIZE + s) == (void *)-1) // Extend the break by s bytes
+    // Attempt to extend the break by s bytes
+    void *new_break = sbrk(BLOCK_SIZE + s);
+    if (new_break == (void *)-1)
+    {
+        // Handle the error, e.g., by setting an error code or printing an error message
+        fprintf(stderr, "Failed to extend heap by %zu bytes.\n", s);
         return NULL;
+    }
 
-    b->size = s; // Corrected from b->size to b->size
+    b->size = s;
     b->prev = last;
     b->next = NULL;
     b->free =  0;
@@ -80,13 +86,13 @@ struct block *fragment_block(struct block *in, size_t s)
 
 	// Create the new block in the remainder space
 	struct block *newBlock = (struct block *)((char *)(in + 1) + s);
-	newBlock->size = remainderSize;
+	newBlock->size = remainderSize; // Subtract the size of the block header
 	newBlock->prev = in;
 	newBlock->next = in->next;
 	newBlock->free = 1; // Set the new block as free
 
 	// Update the current block to reflect the reduced size
-	in->size = newBlockSize;
+	in->size = newBlockSize; // Subtract the size of the block header
 	in->next = newBlock;
 
 	// Insert the new block into the linked list of blocks
@@ -106,16 +112,14 @@ struct block *find_best_fit(size_t s)
 	{
 		if (current->free && current->size >= s)
 		{
-			if (best_fit && current->size < best_fit->size) // Check for NULL before comparison
+			if (best_fit == NULL || current->size < best_fit->size)
-		{
 			{
 				best_fit = current;
 			}
 		}
 		current = current->next;
 	}
-	return best_fit;
+	return best_fit; // This return statement is now outside the while loop
-	}
 }
 
 /// Will find or allocate a memory block.
@@ -197,7 +201,7 @@ void *realloc(void *ptr, size_t new_size)
 /// Will flag the provided memory as free and will defragment other blocks adjacent to it.
 /// @param [in] ptr The memory to flag as free.
 /// @note If all data after the provided memory is free, it will reduce the heap size.
-void my_custom_free(void *ptr)
+void free(void *ptr)
 {
 	if (!ptr)
 	{
@@ -229,7 +233,7 @@ void my_custom_free(void *ptr)
 		b->next = b->next->next;
 		if (b->next)
 		{
-            b->next->prev = b;
+			b->next->prev = b; // Update the prev pointer of the next block
 		}
 	}