Rosetta Code

Pascal's triangle

Generate the opening rows of Pascal's triangle iteratively.

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Sourcerosettacode/popular/pascals_triangle.vibe
def next_row(previous: array<int>) -> array<int>
  if previous.empty?
    return [1]
  end

  row = [1]
  index = 1
  while index < previous.length
    row.push(previous.fetch(index - 1) + previous.fetch(index))
    index = index + 1
  end
  row.push(1)
  row
end

def build_triangle(rows_count: int) -> array<array<int>>
  rows: array<array<int>> = []
  current: array<int> = []
  produced = 0

  while produced < rows_count
    current = next_row(current)
    rows.push(current)
    produced = produced + 1
  end

  rows
end

def run -> array<array<int>>
  build_triangle(7)
end

Output

Click Run example to see the result.

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