[LeetCode]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"].

Credits:

Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.

code:

public class Solution {
   public List<String> summaryRanges(int[] nums) {
 
		 List<String> list = new ArrayList<String>();
		 if(nums==null || nums.length==0)
	            return list;
		 
		 if(nums.length==1){
			list.add(nums[0]+"");
			 return list;
		 }
		 int start=nums[0],end=nums[0];
		 for(int i=1; i<nums.length; i++){
			 
			 if(nums[i-1]+1==nums[i]){
				 end = nums[i];
			 }else{
				
				 addToArr(list,start, end);
				 start = end = nums[i];
			 }
		 }
		 addToArr(list,start, end);
		 
		 return list;
	}
	private void addToArr(List<String> list, int start, int end){
		if(start == end)
			list.add(start+"");
		else
			list.add(start+"->"+end);
	}
}