>>703 Ruby
PLACEHOLDER = [*0..80]

field = 9.times.reduce([]) do |s, y|
s << 9.times.map do |x|
PLACEHOLDER[9 * y + x]
end
end

puts field.map{|r| r.map{'%02d' % _1}.join}

# =>
000102030405060708
091011121314151617
181920212223242526
272829303132333435
363738394041424344
454647484950515253
545556575859606162
636465666768697071
727374757677787980