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12. 整数转罗马数字 ​

为保证权益，题目请参考 12. 整数转罗马数字(From LeetCode).

解决方案1 ​

CPP ​

C++
#include <iostream>
using namespace std;

class Solution
{
public:
    string intToRoman(int num)
    {
        if (num >= 900)
        {
            //M
            string tmp = "";
            while (num >= 1000)
            {
                tmp += "M";
                num -= 1000;
            }
            if (num >= 900)
            {
                tmp += "CM";
                num -= 900;
            }
            return tmp + intToRoman(num);
        }
        else if (num >= 400)
        {
            string tmp = "";
            if (num >= 500)
            {
                tmp += "D";
                num -= 500;
            }
            else
            {
                tmp += "CD";
                num -= 400;
            }
            return tmp + intToRoman(num);
        }
        else if (num >= 90)
        {
            string tmp = "";
            while (num >= 100)
            {
                tmp += "C";
                num -= 100;
            }
            if (num >= 90)
            {
                tmp += "XC";
                num -= 90;
            }
            return tmp + intToRoman(num);
        }
        else if (num >= 40)
        {
            string tmp = "";
            if (num >= 50)
            {
                tmp += "L";
                num -= 50;
            }
            else
            {
                tmp += "XL";
                num -= 40;
            }
            return tmp + intToRoman(num);
        }
        else if (num >= 9)
        {
            string tmp = "";
            while (num >= 10)
            {
                tmp += "X";
                num -= 10;
            }
            if (num >= 9)
            {
                tmp += "IX";
                num -= 9;
            }
            return tmp + intToRoman(num);
        }
        else if (num >= 4)
        {
            string tmp = "";
            if (num >= 5)
            {
                tmp += "V";
                num -= 5;
            }
            else
            {
                tmp += "IV";
                num -= 4;
            }
            return tmp + intToRoman(num);
        }
        else
        {
            string tmp = "";
            while (num > 0)
            {
                tmp += "I";
                num -= 1;
            }
            return tmp;
        }

        return "NULL";
    }
};

int main()
{
    Solution so;
    // cout << so.intToRoman(6) << endl;
    for (int i = 10; i >= 0; --i)
    {
        int n;
        cin >> n;
        cout << so.intToRoman(n) << endl;
    }
    return 0;
}

解决方案2 ​

CPP ​

C++
#include <iostream>
#include <string>
using namespace std;

class Solution
{
public:
    string intToRoman(int num)
    {
        string tmp = "";
        while (num >= 1000)
        {
            tmp += "M";
            num -= 1000;
        }
        if (num >= 900)
        {
            tmp += "CM";
            num -= 900;
        }

        if (num >= 500)
        {
            tmp += "D";
            num -= 500;
        }
        if (num >= 400)
        {
            tmp += "CD";
            num -= 400;
        }

        while (num >= 100)
        {
            tmp += "C";
            num -= 100;
        }
        if (num >= 90)
        {
            tmp += "XC";
            num -= 90;
        }

        if (num >= 50)
        {
            tmp += "L";
            num -= 50;
        }
        if (num >= 40)
        {
            tmp += "XL";
            num -= 40;
        }

        while (num >= 10)
        {
            tmp += "X";
            num -= 10;
        }
        if (num >= 9)
        {
            tmp += "IX";
            num -= 9;
        }

        if (num >= 5)
        {
            tmp += "V";
            num -= 5;
        }
        if (num >= 4)
        {
            tmp += "IV";
            num -= 4;
        }

        while (num > 0)
        {
            tmp += "I";
            num -= 1;
        }

        return tmp;
    }
};

int main()
{
    Solution so;
    // cout << so.intToRoman(6) << endl;
    for (int i = 10; i >= 0; --i)
    {
        int n;
        cin >> n;
        cout << so.intToRoman(n) << endl;
    }
    return 0;
}