Roman numerals

Roman numerals

罗马数字的题目, 注意几个关键的数字即可: (100, 400, 500, 900) -> ('C', 'CD', 'D', 'CM'); (10, 40, 50, 90)->('X', 'XL', 'L', 'XC')

 

 1 def checkio(data):

 2     rel = ''

 3 

 4     thonsand = data / 1000

 5     rel += thonsand * 'M'

 6 

 7     data %= 1000

 8 

 9     table = [['C', 'CD', 'D', 'CM'], ['X', 'XL', 'L', 'XC']] 10 11 pos = 100 12 13 for i in range(0, 2): 14 bit = data / pos 15 if bit > 0: 16 if bit < 4: 17 rel += bit * table[i][0] 18 elif bit == 4: 19 rel += table[i][1] 20 elif bit == 5: 21 rel += table[i][2] 22 elif bit == 9: 23 rel += table[i][3] 24 else: 25 rel += (table[i][2] + table[i][0] * (bit - 5)) 26 27 data %= pos 28 pos /= 10 29 30 if data > 0: 31 unit = ['I', 'II', 'III', 'IV', 'V', 'VI', 'VII', 'VIII', 'IX', 'X'] 32 rel += unit[data - 1] 33 34 #replace this for solution 35 return rel

另外还需注意没有个位数的情况, 即第30行所示

观摩JulianNicholls的代码

 1 elements = { 1000 : 'M', 900 : 'CM', 500 : 'D', 400 : 'CD', 

 2              100 : 'C', 90 : 'XC', 50 : 'L', 40: 'XL', 3 10 : 'X', 9 : 'IX', 5 : 'V', 4: 'IV', 1 : 'I' } 4 5 def checkio(data): 6 roman = '' 7 8 for n in sorted(elements.keys(), reverse=True): 9 while data >= n: 10 roman += elements[n] 11 data -= n 12 13 return roman

  sorted(elements.keys(), reverse=True), 按key从大到小排列; 思路不错, 比数位对应的值大, 即加上该数位对应的字母, 并减去对应的数值, 直到data为0