public class Solution {

    public List<String> summaryRanges(int[] nums) {

        List<String> res = new ArrayList<>();

        if(nums==null||nums.length==0){

            return res;

        }

        for(int i=0;i<nums.length;i++){

            int t = nums[i];

            while(i<nums.length-1&&nums[i]+1==nums[i+1]){

                i++;

            }

            String se = "" + t;

            if(t!=nums[i])

                se = t+"->"+nums[i];

            res.add(se);

        }

        return res;

    }

}