学步园

Given an integer, convert it to a roman numeral.

Input is guaranteed to be within the range from 1 to 3999.

思路：

没有思路。

题解：

class Solution {
public:
    string intToRoman(int num) {
        static const string SYMBOLS="  MDCLXVI";
    
        string ret;
        int start_divisor = 1000;
        int iter = 0;
    
        while(start_divisor != 0)
        {
            // digit separation
            int quotient = num / start_divisor;
            num -= quotient * start_divisor;
            start_divisor /= 10;
    
            if (quotient == 9)
            {
                ret += SYMBOLS[iter + 2];
                ret += SYMBOLS[iter];
            } 
            else if (quotient > 5)
            {
                ret += SYMBOLS[iter + 1];
                ret += string(quotient - 5, SYMBOLS[iter + 2]);
            } else if (quotient == 5)
                ret += SYMBOLS[iter + 1];
            else if (quotient == 4)
            {
                ret += SYMBOLS[iter + 2];
                ret += SYMBOLS[iter + 1];
            } else if (quotient > 0)
                ret += string(quotient, SYMBOLS[iter + 2]);
            iter += 2;
        }
    
        return ret;
    }
};