12. Integer to Roman

Given an integer, convert it to a roman numeral.

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

题意：整数转为罗马序列。

思路：把1000,900,500,400,100,90,50,40,10,9,5,4,1作为基数，然后进行除法和取余运算。

class Solution {
public:
string intToRoman(int num) {
string s;
int base[] = { 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 };
string roman[] = {"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
int i = 0;
while (num){
int j = 0;
j = num / base[i];
num %= base[i];
while (j--){
s += roman[i];
}
i++;
}
return s;
}
};