LeetCode Q118: Pascal's Triangle

Given numRows, generate the first numRows of Pascal's triangle.

For example, given numRows = 5,
Return

[
     [1],
    [1,1],
   [1,2,1],
  [1,3,3,1],
 [1,4,6,4,1]
]

Solution:
Pascal's Triangle: Each element of current row, expect the boundary elements, is the sum of two elements that are directly on the above row.




Round 2 solution: