Runtime5 msBeats83.94%
Memory41.1 MBBeats40.44%
#N228. Summary Ranges
problem link
#solution

class Solution {
    public List<String> summaryRanges(int[] nums) {
        List<String> list = new ArrayList<>();
        if(nums.length==0) return list;
        int a=nums[0], b=nums[0];
        for(int i=1; i<nums.length; i++){
            if(nums[i]-nums[i-1]==1){
                b=nums[i];
            }else{
                if(a!=b) list.add(a+"->"+b);
                else list.add(""+a);
                a=nums[i];
                b=nums[i];
            }
        }
        if(a!=b) list.add(a+"->"+b);
        else list.add(""+a);
        return list;
    }
}