[Leetcode] [Java] Roman to Integer

Topic:

Given a Roman numeral, convert it to an integer.

Input is guaranteed to being within the range from 1 to 3999.

Test instructions

Given a Roman number, convert it to an integer.

The given input is guaranteed to be between 1-3999

Algorithm Analysis:

* Roman Numeral rules:

* 1, a total of 7 Roman numerals, namely I (1), V (5), X (10), L (50), C (100), D (500) and M (1000).

* There is no "0" in Roman numerals.

* 2, repetition: a Roman numeral repeats up to 3 times.

* 3, right plus left minus:

* Lower Roman numerals on the right side of the larger Roman numerals, indicating large numbers plus small numbers.

* On the left of the larger Roman numerals, the smaller Roman numerals indicate that large numbers decrease the numbers.

AC Code:

public class solution{    private  int sss;    public  int Romantoint (String s)    {      map<character, integer> dct=new hashmap<character, Integer > ();      Dct.put (' I ', 1);       Dct.put (' I ', 1);       Dct.put (' V ', 5);       Dct.put (' V ', 5);       Dct.put (' X ', ten);       Dct.put (' x ', ten);       Dct.put (' L ', +);       Dct.put (' l ', +);       Dct.put (' C ', +);       Dct.put (' C ', +);       Dct.put (' D ', +);       Dct.put (' d ', +);      Dct.put (' M ', +);       Dct.put (' m ', +);       int sum = 0, J;      for (int i = 0; i < s.length (); ++i)      {          j = i+1;          if (J < s.length () && Dct.get (S.charat (j)) > Dct.get (S.charat (i)))          {            sum + = Dct.get (S.charat (j) )-Dct.get (S.charat (i));            i = j;          }          else            sum + = Dct.get (S.charat (i));      }      return sum;    }}

Copyright NOTICE: This article is the original article of Bo Master, reprint annotated source

[Leetcode] [Java] Roman to Integer