text:  class Solution:
      def XXX(self, numRows: int) -> List[List[int]]:
          res = []
          for i in range(numRows):
              temp = [1]*(i+1)
              for x in range(1,len(temp)-1):
                  temp[x] = res[-1][x-1]+res[-1][x]
              res.append(temp)
          return res
  
  