Description Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1000 |
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 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: L = 50, V = 5, III = 3.
Example 5:
Input: 1994
Output: “MCMXCIV”
Explanation: M = 1000, CM = 900, XC = 90 and IV = 4.
Analyse 【LeetCode-012 Integer to Roman】没啥好分析的，水题一道，阿拉伯数字转罗马数字。
Code
class Solution {
public:
const int value[13] = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};
const string strs[13] = {"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};
string intToRoman(int num) {
string ans;
for (int i = 0;
i < 13;
i++) {
while (num >= value[i]) {
num -= value[i];
ans = ans + strs[i];
}
}
return ans;
}
};
