Single-byte checksum of a payload
Many lightweight protocols use a one-byte checksum: just the sum of all bytes modulo 256.
- Each element in the payload is a byte value (0–255).
- The checksum is the sum of all bytes modulo 256.
- An empty payload has a checksum of 0.
checksumByte(payload: list<int>) → int
Go needs a compiler and Drill does not host one yet, so this page is the reference rather than an exercise: the problem, worked examples, and the solution in full. To type it out, the same problem runs in Python.
Where you start
func checksumByte(payload []int) int {
}Worked examples
| Call | Result |
|---|---|
checksumByte([]int{1, 2, 3}) | 6 |
checksumByte([]int{255, 1}) | 0 |
checksumByte([]int{}) | 0 |
checksumByte([]int{128, 128}) | 0 |
Hint
Add every element, then take the remainder when divided by 256.
Reference solution in Go
func checksumByte(payload []int) int {
sum := 0
for _, b := range payload {
sum += b
}
return sum % 256
}