[LeetCode] Roman to Integer

Given a roman numeral, convert it to an integer.

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

代码如下:

public class Solution {      public int romanToInt(String s) {     if(s.length()==0) return 0;     HashMap<Character,Integer> map=initMap();     int re=map.get(s.charAt(0));     for(int i=1;i<s.length();i++){     int pre=map.get(s.charAt(i-1));     int cur=map.get(s.charAt(i));     if(cur>pre){     re+=cur-2*pre;     }else{     re+=cur;     }     }     return re;     }     public HashMap<Character,Integer> initMap(){     HashMap<Character,Integer> map=new HashMap<Character, Integer>();     map.put('I', 1);     map.put('V', 5);     map.put('X', 10);     map.put('L', 50);     map.put('C', 100);     map.put('D', 500);     map.put('M', 1000);      return map;     } }