罗马数字转整数

罗马数字转整数

public class tt {
    public int val(String s){
        int sum=0;
        int flag=getke(s.charAt(0));
        for(int i=1;i<s.length();i++){
            int num = getke(s.charAt(i));
            if(flag<num){
                sum-=flag;
            }
            else{
                sum+=flag;
            }
            flag=num;
        }
        return sum+flag;
    }
    public int getke(char ch){
        switch (ch){
            case 'I':return 1;
            case 'V':return 5;
            case 'X':return 10;
            case 'L':return 50;
            case 'C':return 100;
            case 'D':return 500;
            case 'M':return 1000;
            default:return 0;
        }
    }
}