How does DISTINCT work?

Go does not have a built-in DISTINCT function like SQL, but typically, DISTINCT refers to the operation of removing duplicates from a slice.

To implement DISTINCT in Go, you can use a map to track already encountered elements. For example:

func Distinct(slice []int) []int {
    seen := make(map[int]struct{})
    result := []int{}
    for _, v := range slice {
        if _, ok := seen[v]; !ok {
            seen[v] = struct{}{}
            result = append(result, v)
        }
    }
    return result
}

Thus, DISTINCT works by storing unique values in a map and creating a new slice without duplicates.