[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);
    }
}