Generates nth look-and-say sequence

look-and-say.go

func countAndSay(n int) string {
    prev := "1"
    if n == 1 {
        return prev
    }
    for i := 2; i <= n; i++ {
        prev = compute(prev)
    }
    return prev
}

func compute(term string) string {
    var sb strings.Builder
    prev := rune(term[0])
    var count int = 0
    for _, v := range term {
        if v == prev {
            count++
        } else {
            fmt.Fprintf(&sb, "%d", count)
            sb.WriteRune(prev)
            prev = v
            count = 1
        }
    }
    fmt.Fprintf(&sb, "%d", count)
    sb.WriteRune(prev)
    return sb.String()
}