conway's game of life rb

# ดัดแปลงจากตัวอย่างในภาษา fe (github.com/rxi/fe)/ มาเป็น ruby

def print_grid(grid)
    grid.each do |row|
        print row.map {|cell| cell==0?" ":"#"}, "\n"
    end
end

def get_cell(grid, x, y)
    if x < 0 or y < 0 or y >= grid.length or x >= grid[y].length
        return 0
    end
    grid[y][x]
end

def next_cell(grid, cell, x, y)
    n = get_cell(grid, (x - 1), (y - 1)) +
        get_cell(grid, (x - 1), y) +
        get_cell(grid, (x - 1), (y + 1)) +
        get_cell(grid, x, (y - 1)) +
        get_cell(grid, x, (y + 1)) +
        get_cell(grid, (x + 1), (y - 1)) +
        get_cell(grid, (x + 1), y) +
        get_cell(grid, (x + 1), (y + 1))
    if cell == 1 and (n == 2 or n == 3)
        return 1
    end
    if cell == 0 and n == 3
        return 1
    end
    0
end

def next_grid(grid)
    y = -1
    grid.map {|row|
      y += 1
      x = -1
      row.map {|cell|
        x += 1
        next_cell grid,cell,x,y
      }
    }
#    ngrid = []
#    for y in 0...grid.length
#        ngrid[y]=[]
#        for x in 0...grid[y].length
#            ngrid[y][x] = next_cell grid, grid[y][x], x, y
#        end
#    end
#    ngrid
end

def life(n, grid)
    i = 1
    puts grid.length
    while i <= n
        puts ">> iteration #{i}"
        print_grid grid
        puts
        grid = next_grid grid
        i += 1
    end
end

# blinker in a 3x3 universe
life(2, [
    [0, 1, 0],
    [0, 1, 0],
    [0, 1, 0]
])


# glider in an 8x8 universe
life(22, [
    [0, 0, 1, 0, 0, 0, 0, 0],
    [0, 0, 0, 1, 0, 0, 0, 0],
    [0, 1, 1, 1, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0, 0]
])