[LeetCode]Summary Ranges

public class Solution {
public List<String> summaryRanges(int[] nums) {
List<String> result = new ArrayList<String>();
int length = nums.length;
int left = 0;
for (int i = 0; i < length; i++) {
if (i + 1 == length || nums[i] + 1 != nums[i + 1]) {
result.add(helper(nums, left, i));
left = i + 1;
}
}
return result;
}
public String helper(int[] nums, int left, int right) {
if (left == right) {
return String.valueOf(nums[left]);
} else {
return String.valueOf(nums[left]) + "->" + String.valueOf(nums[right]);
}
}
}