LeetCode #12 简单题（给定了范围，直接硬编码就好了。。）

题目：整数转罗马数字

题解：范围限定在0-3999，硬编码就好- -懒得想逻辑了

class Solution {
public:
    string intToRoman(int num) {
        int a = num / 1000;
        int b = (num / 100) % 10;
        int c = (num / 10) % 10;
        int d = num % 10;
        string ans;
        for (int i = 0; i < a; ++i)ans = ans + "M";
        if (b == 9)ans = ans + "CM";
        else if (b == 8)ans = ans + "DCCC";
        else if (b == 7)ans = ans + "DCC";
        else if (b == 6)ans = ans + "DC";
        else if (b == 5)ans = ans + "D";
        else if (b == 4)ans = ans + "CD";
        else if (b == 3)ans = ans + "CCC";
        else if (b == 2)ans = ans + "CC";
        else if (b == 1)ans = ans + "C";

        if (c == 9)ans = ans + "XC";
        else if (c == 8)ans = ans + "LXXX";
        else if (c == 7)ans = ans + "LXX";
        else if (c == 6)ans = ans + "LX";
        else if (c == 5)ans = ans + "L";
        else if (c == 4)ans = ans + "XL";
        else if (c == 3)ans = ans + "XXX";
        else if (c == 2)ans = ans + "XX";
        else if (c == 1)ans = ans + "X";

        if (d == 9)ans = ans + "IX";
        else if (d == 8)ans = ans + "VIII";
        else if (d == 7)ans = ans + "VII";
        else if (d == 6)ans = ans + "VI";
        else if (d == 5)ans = ans + "V";
        else if (d == 4)ans = ans + "IV";
        else if (d == 3)ans = ans + "III";
        else if (d == 2)ans = ans + "II";
        else if (d == 1)ans = ans + "I";

        return ans;
    }
};