new_contents: class Solution:
      # @param {integer[]} nums
      # @return {string[]}
  
      def summaryRanges(self, nums):
          res = []
          for num in nums:
              if not res or num-res[-1][-1] > 1:
                  res += [],
              res[-1][1:] = num,
          return ['->'.join(map(str, r)) for r in res]
  
subject: add solution for Summary Ranges