arabic(0) = 1000
arabic(1) = 900
arabic(2) = 500
arabic(3) = 400
arabic(4) = 100
arabic(5) = 90
arabic(6) = 50
arabic(7) = 40
arabic(8) = 10
arabic(9) = 9
arabic(10) = 5
arabic(11) = 4
arabic(12) = 1
roman(0) = "M"
roman(1) = "CM"
roman(2) = "D"
roman(3) = "CD"
roman(4) = "C"
roman(5) = "XC"
roman(6) = "L"
roman(7) = "XL"
roman(8) = "X"
roman(9) = "IX"
roman(10) = "V"
roman(11) = "IV"
roman(12) = "I"
以上是十进制和罗马数字之间的对应关系，求罗马转10的程序