Refine 012_Integer_to_Roman

qiyuangong · qiyuangong · commit b5166888c268 · 2020-10-07T23:43:37.000+08:00
diff --git a/README.md b/README.md
@@ -21,7 +21,7 @@ I'm currently working on [Analytics-Zoo](https://github.com/intel-analytics/anal
 | 8 | [String to Integer (atoi)](https://leetcode.com/problems/string-to-integer-atoi/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/008_String_to_Integer(atoi).py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/008_String_to_Integer(atoi).java) | Overflow, Space, and negative number |
 | 9 | [Palindrome Number](https://leetcode.com/problems/palindrome-number/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/009_Palindrome_Number.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/009_Palindrome_Number.java) | Get the len and check left and right with 10^len, 10 |
 | 11 | [Container With Most Water](https://leetcode.com/problems/container-with-most-water/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/011_Container_With_Most_Water.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/011_Container_With_Most_Water.java) | 1. Brute Force, O(n^2) and O(1)<br>2. Two points, O(n) and O(1)  |
-| 12 | [Integer to Roman](https://leetcode.com/problems/integer-to-roman/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/012_Integer_to_Roman.py) | [Background knowledge](http://www.rapidtables.com/convert/number/how-number-to-roman-numerals.htm) Just like 10-digit number, divide and minus |
+| 12 | [Integer to Roman](https://leetcode.com/problems/integer-to-roman/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/012_Integer_to_Roman.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/012_Integer_to_Roman.java) | [Background knowledge](http://www.rapidtables.com/convert/number/how-number-to-roman-numerals.htm) Just like 10-digit number, divide and minus |
 | 13 | [Roman to Integer](https://leetcode.com/problems/roman-to-integer/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/013_Roman_to_Integer.py) | Add all curr, if curr > prev, then need to subtract 2 * prev |
 | 15 | [3Sum](https://leetcode.com/problems/3sum/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/015_3Sum.py) | 1. Sort and O(n^2) search with three points <br>2. Multiple Two Sum (Problem 1) |
 | 16 | [3Sum Closest](https://leetcode.com/problems/3sum-closest/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/016_3Sum_Closest.py) | Sort and Multiple Two Sum check abs|
diff --git a/java/012_Integer_to_Roman.java b/java/012_Integer_to_Roman.java
@@ -0,0 +1,23 @@
+class Solution {
+	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();
+	}
+}
diff --git a/java/012_integertoroman.java b/java/012_integertoroman.java
