leetcode-12-java

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.

Symbol       Value
I             1
V             5
X             10
L             50
C             100
D             500
M             1000
For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, which is simply X + II. 
The number twenty seven is written as XXVII, which is XX + V + II

class Solution {
   private static List<Point> list = new ArrayList<Point>(){{
            add(new Point(1000, "M"));
            add(new Point(900, "CM"));
            add(new Point(500, "D"));
            add(new Point(400, "CD"));
            add(new Point(100, "C"));
            add(new Point(90, "XC"));
            add(new Point(50, "L"));
            add(new Point(40, "XL"));
            add(new Point(10, "X"));
            add(new Point(9, "IX"));
            add(new Point(5, "V"));
            add(new Point(4, "IV"));
            add(new Point(1, "I"));
        }
    };
    public static String intToRoman(int num) {

        int index = 0;
        StringBuffer sb = new StringBuffer();
        while (num != 0) {
            Point point = list.get(index);
            if (num - point.getBase() >= 0) {
                sb.append(point.getDesc());
                num -= point.getBase();
            } else {
                index ++;
            }
        }
        return sb.toString();
    }

    private static class Point {
        private Integer base;

        private String desc;

        private Point(Integer base, String desc) {
            this.base = base;
            this.desc = desc;
        }

        public Integer getBase() {
            return base;
        }

        public void setBase(Integer base) {
            this.base = base;
        }

        public String getDesc() {
            return desc;
        }

        public void setDesc(String desc) {
            this.desc = desc;
        }
    }
}