zoukankan      html  css  js  c++  java
  • 12. Integer to Roman

    Roman numerals are represented by seven different symbols: IVXLCD and M.

    Symbol       Value
    I             1
    V             5
    X             10
    L             50
    C             100
    D             500
    M             1000

    For example, two is written as II in Roman numeral, just two one's added together. Twelve is written as, XII, which is simply X + II. The number twenty seven is written as XXVII, which is XX + V + II.

    Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII. Instead, the number four is written as IV. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as IX. There are six instances where subtraction is used:

    • I can be placed before V (5) and X (10) to make 4 and 9. 
    • X can be placed before L (50) and C (100) to make 40 and 90. 
    • C can be placed before D (500) and M (1000) to make 400 and 900.

    Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999.

    Example 1:

    Input: 3
    Output: "III"

    Example 2:

    Input: 4
    Output: "IV"

    Example 3:

    Input: 9
    Output: "IX"

    Example 4:

    Input: 58
    Output: "LVIII"
    Explanation: C = 100, L = 50, XXX = 30 and III = 3.
    

    Example 5:

    Input: 1994
    Output: "MCMXCIV"
    Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.

    my code:

    class Solution {
    public:
        string intToRoman(int num) {
            string str[4][9] = {{"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"}
                               };
            string ans = "";
            int count = 0, flag;
            while (num) {
                flag = num % 10;
                if (flag)
                    ans = str[count][flag-1] + ans;
                num /= 10;
                count++;
            }
            return ans;
        }
    };
    

    Runtime: 56 ms, faster than 46.31% of C++ online submissions for Integer to Roman.

    永远渴望,大智若愚(stay hungry, stay foolish)
  • 相关阅读:
    CShop Project 082: 获取分页数据模型并传递到页面上
    CShop Project 08: 展示不同类型的商品
    CShop Project 08: 开发商品分类的查询和展示
    119 类和数据类型
    118 对象的绑定方法
    117 对象的属性查找顺序
    116 定制对象独有特征
    115 类和对象
    114 面向对象编程介绍
    113 面向对象程序设计的由来(了解)
  • 原文地址:https://www.cnblogs.com/h-hkai/p/9733295.html
Copyright © 2011-2022 走看看