[Leetcode] (python): 013-roman to Integer

Source of the topic:

https://leetcode.com/problems/roman-to-integer/

Test Instructions Analysis:

The title, contrary to the previous one, is the conversion of Roman numerals into Arabic numerals.

Topic Ideas:

Just know how the Roman numerals and Arabic numerals are converted. First make a dictionary of characters and values, {' I ': 1, ' V ': 5, ' X ': Ten, ' L ': +, ' C ': +, ' D ': +, ' M ': 1000}; If you find that the input string is smaller than the previous one, then there is 4,9, Then subtract the value of the previous character by two times.

Code (Python):

1 classsolution (object):2     defRomantoint (self, s):3         """4 : Type S:str5 : Rtype:int6         """7D = {'I': 1,'V'75A'X': 10,'L': 50,'C': 100,'D': 500,'M': 1000}8Ans =09Size =Len (s)Teni =0 One          whileI <Size: A             ifI > 0 andD[s[i]] > D[s[i-1]]: -Ans + = d[s[i]]-2 * d[s[i-1]] -             Else: theAns + =D[s[i]] -i + = 1 -         returnAns

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Reprint Please specify source: http://www.cnblogs.com/chruny/p/4817835.html

[Leetcode] (python): 013-roman to Integer