Summary Interval - Teeeeeebag/LeetCode GitHub Wiki

public class Solution {
    private void addInterval(ArrayList<String> res, int low, int high){
        if (low == high){
            res.add(String.valueOf(low));
        } else {
            res.add(String.valueOf(low) + "->" + String.valueOf(high));
        }
    }
    public List<String> summaryRanges(int[] nums) {
        ArrayList<String> res = new ArrayList<>();
        if (nums.length == 0){
            return res;
        }
        int start = 0, end = 0;
        while (start < nums.length){
            end = start + 1;
            while (end < nums.length && nums[end] == nums[end-1] + 1){
                ++end;
            }
            addInterval(res, nums[start], nums[end-1]);
            start = end;
        }
        return res;
    }
}