12 - Integer to Roman

 JAVA

• class Solution {
      public String intToRoman(int num) {
          List<String> cs
              = List.of("M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I");
          List<Integer> vs = List.of(1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1);
          StringBuilder ans = new StringBuilder();
          for (int i = 0, n = cs.size(); i < n; ++i) {
              while (num >= vs.get(i)) {
                  num -= vs.get(i);
                  ans.append(cs.get(i));
              }
          }
          return ans.toString();
      }
  }

C++

• class Solution {
  public:
      string intToRoman(int num) {
          vector<string> cs = {"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
          vector<int> vs = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};
          string ans;
          for (int i = 0; i < cs.size(); ++i) {
              while (num >= vs[i]) {
                  num -= vs[i];
                  ans += cs[i];
              }
          }
          return ans;
      }
  };