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
For example, two is written as II in Roman numeral, just two one's
added together. Twelve is written as, XII, which is simply X +
II. The number twenty seven is written as XXVII, which is
XX + V + II.
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 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.