From cassido's January 23, 2023 Newsletter

missingBits.go

package main

import (
	"fmt"
	"strconv"
)

func main() {
	val1 := missingBits([]int{1, 2, 3, 4, 20, 21, 22, 23})
	fmt.Println(val1)
	val2 := missingBits([]int{1, 2, 3, 5, 6})
	fmt.Println(val2)
	val3 := missingBits([]int{1, 3, 20, 27})
	fmt.Println(val3)
}

func missingBits(ns []int) []string {
	var out []string

	for i, x := range ns {
		xStr := strconv.Itoa(x)
		out = append(out, xStr)

		if i+1 == len(ns) {
			break
		}

		next := ns[i+1]
		diff := next - x

		if diff == 2 {
			next_str := strconv.Itoa(x + 1)
			out = append(out, next_str)
		}

		if diff > 2 {
			out = append(out, "...")
		}
	}

	return out
}