Array helpers with memcpy

The code

Embedded C for Cortex-M. It compiles. There are 3 real bugs in it: the kind that pass a bench test and fail in the field.

typedef struct {
    uint16_t id;
    uint16_t value;
} item_t;

void clear_items(item_t *items)
{
    memset(items, 0, sizeof(items));
}

void remove_item(item_t *items, size_t count, size_t idx)
{
    memcpy(&items[idx], &items[idx + 1],
           (count - idx) * sizeof(item_t));
}

What an interviewer expects

• Point to each line you'd stop in a code review.
• Say what actually breaks: the failure mode, not just the rule it violates.
• Fix it, then defend the fix when asked the follow-up.

The bugs, reference fixes and the follow-up question are in the practice app, after you've tried it.

Companies that test this

Matched on the skills each company's embedded roles emphasise.

Related challenges