Create 012_integertoroman.java (qiyuangong#12)

Added JAVA solution for leetcode 012 integertoroman, by @arun-aditya

Author: arun-aditya

java/012_integertoroman.java

@@ -0,0 +1,21 @@
+public String intToRoman(int num) {
+	Map<Integer, String> map = new HashMap();
+	map.put(1, "I"); map.put(5, "V"); map.put(10, "X");
+	map.put(50, "L"); map.put(100, "C"); map.put(500, "D"); map.put(1000, "M");
+	map.put(4, "IV"); map.put(9, "IX"); map.put(40, "XL"); map.put(90, "XC");
+	map.put(400, "CD"); map.put(900, "CM");
+
+	int[] sequence = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};
+
+	StringBuffer sb = new StringBuffer();
+	for (int i=0; i<sequence.length; i++) {
+		int base = sequence[i];
+
+		while (num >= base) {
+			sb.append(map.get(base));
+			num -= base;
+		}
+	}
+
+	return sb.toString();
+}