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# -*- coding: utf8 -*-
‘‘‘
__author__ = ‘dabay.wang@gmail.com‘
https://oj.leetcode.com/problems/integer-to-roman/
Integer to Roman
Given an integer, convert it to a roman numeral.
Input is guaranteed to be within the range from 1 to 3999.
===Comments by Dabay===
先google一下罗马数字的表示:
I - 1
V - 5
X - 10
L - 50
C - 100
D - 500
M - 1000
主要问题是会有一些4,40之类的表示。
比如999的时候,因为900可以表示为CM,所以需要先生成CM,数字减少900为99;而不是减少500为499.
可以生成一个有序的键值表,每次减少最大的,直到剩下的数小于hash表中的最大数,把这个最大数删掉继续处理。
‘‘‘
class Solution:
# @return a string
def intToRoman(self, num):
pairs = [
(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")
]
res = ""
for (n, s) in pairs:
while num >= n:
res = res + s
num = num - n
return res
def main():
s = Solution()
print s.intToRoman(6)
if __name__ == "__main__":
import time
start = time.clock()
main()
print "%s sec" % (time.clock() - start)
[LeetCode][Python]Integer to Roman
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原文地址:http://www.cnblogs.com/Dabay/p/4231423.html