Write pascal(n) returning the first n rows of Pascal's triangle: pascal(4) → [[1],[1,1],[1,2,1],[1,3,3,1]].
pascal(4) → [[1], [1, 1], [1, 2, 1], [1, 3, 3, 1]]
pascal(0) → []
Submit runs 4 tests, including hidden edge cases.
Run your code to see the output here.