[LintCode] Integer to Roman 整数转化成罗马数字-白红宇

Given an integer, convert it to a roman numeral.

The number is guaranteed to be within the range from 1 to 3999.

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Clarification

What is Roman Numeral?

Example

4 -> IV

12 -> XII

21 -> XXI

99 -> XCIX

more examples at:

LeetCode上的原题，请参见我之前的博客。

解法一：

class Solution {public:    /**     * @param n The integer     * @return Roman representation     */    string intToRoman(int n) {        string res = "";        vector
      
       
        > v {
    {
    "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"}, {
    "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"}, {
    "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"}, {
    "M", "MM", "MMM"}};        int cnt = 1000;        for (int i = 3; i >= 0; --i) {            int t = n / cnt;            if (t) res += v[i][t - 1];            n %= cnt;            cnt /= 10;        }        return res;    }};

解法二：

class Solution {public:    /**     * @param n The integer     * @return Roman representation     */    string intToRoman(int n) {        string res = "";        vector
      
        val {
    1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1};        vector
       
         str{
    "M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"};        for (int i = 0; i < val.size(); ++i) {            while (n >= val[i]) {                n -= val[i];                res += str[i];            }           }        return res;    }};

解法三：

class Solution {public:    /**     * @param n The integer     * @return Roman representation     */    string intToRoman(int n) {        string res = "";        vector
      
        v1 {
    "", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"};        vector
       
         v2 {
    "", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"};        vector
        
          v3 {
    "", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"};        vector
         
           v4 {
    "", "M", "MM", "MMM"};        return v4[n / 1000] + v3[(n % 1000) / 100] + v2[(n % 100) / 10] + v1[n % 10];    }};

本文转自博客园Grandyang的博客，原文链接：，如需转载请自行联系原博主。