[LeetCode]-011-Roman_to_Integer

Given a roman numeral, convert it to an integer.

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

题目大意：把罗马数字转换成的整数

遍历每个字符，前一个字符比后一个字符小，相减

 public class Solution{
     public int romanToInt(String s) {
         s = s.trim();
         if (null == s || "".equals(s))
             return 0;
         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);
         int cur = s.length()-1;
         int sum = map.get(s.charAt(cur));
         int tmp1,tmp2;
         cur--;
         while(cur>=0){
             tmp1 = map.get(s.charAt(cur+1));
             tmp2 = map.get(s.charAt(cur));
             if(tmp2<tmp1)
                 sum = sum - tmp2;
             else
                 sum = sum + tmp2;
             cur--;
         }
         return sum;
     }

     public static void main(String[] args){
         String param = "CMXLVI";
         if(args.length==1){
             param = args[0];
         }
         Solution solution = new Solution();
         int res = solution.romanToInt(param);
         System.out.println(res);
     }
 }