text:  class Solution:
      def XXX(self, numRows: int) -> List[List[int]]:
          result = [[1]]
          for i in range(numRows-1):
              pre = result[i]
              if len(pre) == 1:
                  result.append([1,1])
              else:
                  result.append([1] + [pre[i] + pre[i+1] for i in range(len(pre)-1)] + [1])
          
          return result
  
  
  