add: 0012 [cpp]

cpp/more/0012.cpp

@@ -0,0 +1,25 @@
+#include <iostream>
+#include <string>
+#include <vector>
+
+class Solution {
+private:
+	const inline static std::vector<std::vector<std::string>> RN = {
+			{"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"},
+			{"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"},
+			{"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"},
+			{"", "M", "MM", "MMM"}
+	};
+public:
+	static std::string intToRoman(int num) {
+		return RN[3][num / 1000] +
+			   RN[2][(num / 100) % 10] +
+			   RN[1][(num % 100) / 10] +
+			   RN[0][num % 10];
+	}
+};
+
+int main() {
+	std::cout << Solution::intToRoman(1994);
+	return 0;
+}