package q228

import (
	"fmt"
	"strconv"
)

func addToRanges(output []string, a, b int) []string {
	if a == b {
		return append(output, strconv.FormatInt(int64(a), 10))
	}
	return append(output, fmt.Sprintf("%d->%d", a, b))
}

func summaryRanges(nums []int) []string {
	if len(nums) == 0 {
		return nil
	}

	output := []string{}
	l := 0
	for r := 1; r < len(nums); r++ {
		if nums[r]-nums[r-1] != 1 {
			output = addToRanges(output, nums[l], nums[r-1])
			l = r
		}
	}
	output = addToRanges(output, nums[l], nums[len(nums)-1])
	return output
}

var _ = summaryRanges