力扣直通车

13. 罗马数字转整数

问题描述

提示

代码

package com.leetcode.simple;

/**
 * @author 花琪尧
 * @date 2022/7/29 22:05:27
 */
public class P13_RomanToInt {
    public int romanToInt(String s) {
        int sum = 0;
        if (s.contains("IV")) {
            sum += 4;
            s = s.replace("IV", "");
        }
        if (s.contains("IX")) {
            sum += 9;
            s = s.replace("IX", "");
        }
        if (s.contains("XL")) {
            sum += 40;
            s = s.replace("XL", "");
        }
        if (s.contains("XC")) {
            sum += 90;
            s = s.replace("XC", "");
        }
        if (s.contains("CD")) {
            sum += 400;
            s = s.replace("CD", "");
        }
        if (s.contains("CM")) {
            sum += 900;
            s = s.replace("CM", "");
        }
        for (int i = 0; i < s.length(); i++) {
            char ch = s.charAt(i);
            switch (ch) {
                case 'I':
                    sum += 1;
                    break;
                case 'V':
                    sum += 5;
                    break;
                case 'X':
                    sum += 10;
                    break;
                case 'L':
                    sum += 50;
                    break;
                case 'C':
                    sum += 100;
                    break;
                case 'D':
                    sum += 500;
                    break;
                case 'M':
                    sum += 1000;
                    break;
                default:
                    System.out.println("输入错误！！！");
                    System.exit(0);
            }
        }
        return sum;
    }

    //测试类
    public static void main(String[] args) {
        P13_RomanToInt rti = new P13_RomanToInt();
        System.out.println(rti.romanToInt("LVIII"));
    }
}

执行结果