1
# Runtime: 38 ms (Top 76.97%) | Memory: 13.8 MB (Top 98.42%)
2

3

4
class Solution(object):
5
    def summaryRanges(self, nums):
6

7
        if len(nums) == 0:
8
            return []
9

10
        l, r = 0, 0
11
        res = []
12

13
        while l <= r and r <= len(nums):
14

15
            if r == 0:
16
                r += 1
17

18
            while r < len(nums) and r > 0 and nums[r - 1] == nums[r] - 1:
19
                r += 1
20

21
            if r - 1 == l:
22
                res.append(str(nums[r - 1]))
23
            else:
24
                res.append(str(nums[l]) + "->" + str(nums[r - 1]))
25

26
            l = r
27
            r += 1
28

29
        return res