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"].
此题方法是，遍历一遍数组元素，设定当前数组元素为a，当cur的后面的元素-cur的元素==1的时候，i++操作，代码如下：
public class Solution {
public List<String> summaryRanges(int[] nums) {
List<String> res= new ArrayList<String>();
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]) res.add(nums[i]+"");
else res.add(a+"->"+nums[i]);
}
return res;
}
}