Summary ranges

Given a sorted integer array without duplicates, return the summary of its ranges.

For example, given [0,1,2,4,5,7], return ["0->2","4->5","7"].

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