From a599172b4f3419364845ed70958bad6e4027432e Mon Sep 17 00:00:00 2001
From: dazer007 <ab601026460@163.com>
Date: Fri, 19 Jan 2024 22:30:22 +0800
Subject: [PATCH 1/2] =?UTF-8?q?NumberUtil=E6=96=B0=E5=A2=9E=E6=AD=A3?=
 =?UTF-8?q?=E6=95=B4=E6=95=B0=E8=BD=AC=E7=BD=97=E9=A9=AC=E6=95=B0=E5=AD=97?=
 =?UTF-8?q?=EF=BC=8C=E9=99=90=E5=88=B6[1,3999]=E7=9A=84=E6=AD=A3=E6=95=B4?=
 =?UTF-8?q?=E6=95=B0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../dromara/hutool/core/math/NumberUtil.java  | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/hutool-core/src/main/java/org/dromara/hutool/core/math/NumberUtil.java b/hutool-core/src/main/java/org/dromara/hutool/core/math/NumberUtil.java
index 561a86959..6088a4395 100644
--- a/hutool-core/src/main/java/org/dromara/hutool/core/math/NumberUtil.java
+++ b/hutool-core/src/main/java/org/dromara/hutool/core/math/NumberUtil.java
@@ -1554,4 +1554,37 @@ public class NumberUtil extends NumberValidator {
 		}
 		return equals(toBigDecimal(n), BigDecimal.ZERO);
 	}
+
+	/**
+	 * 整数转罗马数字<br>
+	 * 限制：[1,3999]的正整数
+	 * <ul>
+	 *     <li>I 1</li>
+	 *     <li>V 5</li>
+	 *     <li>X 10</li>
+	 *     <li>L 50</li>
+	 *     <li>C 100</li>
+	 *     <li>D 500</li>
+	 *     <li>M 1000</li>
+	 * </ul>
+	 *
+	 * @param num [1,3999]的正整数
+	 * @return 罗马数字
+	 * @since 6.0.0
+	 * @author dazer
+	 */
+	public static String intToRoman(int num) {
+		if (num > 3999 || num < 1 ){
+			return "";
+		}
+		String[] thousands = {"", "M", "MM", "MMM"};
+		String[] hundreds = {"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"};
+		String[] tens = {"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"};
+		String[] ones = {"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"};
+
+		return thousands[num / 1000] +
+			hundreds[(num % 1000) / 100] +
+			tens[(num % 100) / 10] +
+			ones[num % 10];
+	}
 }

From c3e8d11238cf412ffbb5d368a48c75a157fb9926 Mon Sep 17 00:00:00 2001
From: dazer007 <ab601026460@163.com>
Date: Sat, 20 Jan 2024 22:31:47 +0800
Subject: [PATCH 2/2] =?UTF-8?q?NumberUtil=E6=96=B0=E5=A2=9EromanToInt?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../dromara/hutool/core/math/NumberUtil.java  | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/hutool-core/src/main/java/org/dromara/hutool/core/math/NumberUtil.java b/hutool-core/src/main/java/org/dromara/hutool/core/math/NumberUtil.java
index 6088a4395..2002662b0 100644
--- a/hutool-core/src/main/java/org/dromara/hutool/core/math/NumberUtil.java
+++ b/hutool-core/src/main/java/org/dromara/hutool/core/math/NumberUtil.java
@@ -1587,4 +1587,55 @@ public class NumberUtil extends NumberValidator {
 			tens[(num % 100) / 10] +
 			ones[num % 10];
 	}
+
+	/**
+	 * 罗马数字转整数<br>
+	 * @param roman 罗马字符
+	 * @return 整数
+	 * @throws IllegalArgumentException 如果传入非罗马字符串，抛出异常
+	 * @since 6.0.0
+	 * @author dazer
+	 */
+	public static int romanToInt(String roman) {
+		int result = 0;
+		int prevValue = 0;
+		int currValue = 0;
+
+		for (int i = roman.length() - 1; i >= 0; i--) {
+			char c = roman.charAt(i);
+			switch (c) {
+				case 'I':
+					currValue = 1;
+					break;
+				case 'V':
+					currValue = 5;
+					break;
+				case 'X':
+					currValue = 10;
+					break;
+				case 'L':
+					currValue = 50;
+					break;
+				case 'C':
+					currValue = 100;
+					break;
+				case 'D':
+					currValue = 500;
+					break;
+				case 'M':
+					currValue = 1000;
+					break;
+				default:
+					throw new IllegalArgumentException("Invalid Roman character: " + c);
+			}
+			if (currValue< prevValue) {
+				result -= currValue;
+			} else {
+				result += currValue;
+			}
+
+			prevValue = currValue;
+		}
+		return result;
+	}
 }