Java Solution with TreeMap

  • 0

    The treemap has default increasing order in keys. Need to define a comparator in decreasing order.

    class Solution {
        public String intToRoman(int num) {
            TreeMap<Integer, String> map = new TreeMap<>((a,b) -> (b - a));
            map.put(1000, "M");
            map.put(900, "CM");
            map.put(500, "D");
            map.put(400, "CD");
            map.put(100, "C");
            map.put(90, "XC");
            map.put(50, "L");
            map.put(40, "XL");
            map.put(10, "X");
            map.put(9, "IX");
            map.put(5, "V");
            map.put(4, "IV");
            map.put(1, "I");
            String result = "";
            for (Map.Entry<Integer, String> entry : map.entrySet()) {
                while (num >= entry.getKey()) {
                    result += entry.getValue();
                    num -= entry.getKey();
            return result;

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