系列索引:【菜菜的刷题日记】被LeetCode用Python狂虐的那段日子
【题目】
题目链接:https://leetcode-cn.com/problems/integer-to-roman/
【官方思路】
方法一:模拟
class Solution:
VALUE_SYMBOLS = [
(1000, "M"),
(900, "CM"),
(500, "D"),
(400, "CD"),
(100, "C"),
(90, "XC"),
(50, "L"),
(40, "XL"),
(10, "X"),
(9, "IX"),
(5, "V"),
(4, "IV"),
(1, "I"),
]
def intToRoman(self, num: int) -> str:
roman = list()
for value, symbol in Solution.VALUE_SYMBOLS:
while num >= value:
num -= value
roman.append(symbol)
if num == 0:
break
return "".join(roman)
方法二:硬编码数字
class Solution:
THOUSANDS = ["", "M", "MM", "MMM"]
HUNDREDS = ["", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"]
TENS = ["", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"]
ONES = ["", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"]
def intToRoman(self, num: int) -> str:
return Solution.THOUSANDS[num // 1000] + \
Solution.HUNDREDS[num % 1000 // 100] + \
Solution.TENS[num % 100 // 10] + \
Solution.ONES[num % 10]
【我的代码】
主要使用了字典的遍历,代码比较简洁易懂,但是效率不高,仅供参考~
class Solution:
def intToRoman(self, num: int) -> str:
value = {1000: 'M', 900: 'CM', 500: 'D', 400: 'CD', 100: 'C', 90: 'XC',
50: 'L', 40: 'XL', 10: 'X', 9: 'IX', 5: 'V', 4: 'IV', 1: 'I'}
strs = ""
for key, val in value.items():
while num >= key:
num -= key
strs += val
return strs
【思考】
早睡早起是我遥不可及的梦