[LintCode] Integer to Roman
Given an integer, convert it to a roman numeral.
The number is guaranteed to be within the range from 1 to 3999.
Clarification
Example
4 -> IV
12 -> XII
21 -> XXI
99 -> XCIX
1. Create a mapping between the roman symbols and their integer values.
2. Starting from the biggest symbol, check the number of this symbol needed
to construct the input integer. Add this many symbols to the result string builder if needed.
Subtract the added value from the input integer.
3. Proceed to the next biggest symbol and repeat step 2 until the input integer becomes 0.
1 public class Solution { 2 public String intToRoman(int num) { 3 if(num <= 0) { 4 return ""; 5 } 6 int[] nums = {1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1}; 7 String[] symbols = {"M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"}; 8 StringBuilder res = new StringBuilder(); 9 int digit = 0; 10 while (num > 0) { 11 int times = num / nums[digit]; 12 num -= nums[digit] * times; 13 for ( ; times > 0; times--) { 14 res.append(symbols[digit]); 15 } 16 digit++; 17 } 18 return res.toString(); 19 } 20 }
Related Problems
Roman to Integer
Integer to English
