Integer to Roman

描述

Given an integer, convert it to a roman numeral.

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

分析

无

代码

  1. // Integer to Roman
  2. // 时间复杂度O(num)，空间复杂度O(1)
  3. class Solution {
  4. public:
  5.     string intToRoman(int num) {
  6.         const int radix[] = {1000, 900, 500, 400, 100, 90,
  7.                 50, 40, 10, 9, 5, 4, 1};
  8.         const string symbol[] = {"M", "CM", "D", "CD", "C", "XC",
  9.                 "L", "XL", "X", "IX", "V", "IV", "I"};
  11.         string roman;
  12.         for (size_t i = 0; num > 0; ++i) {
  13.             int count = num / radix[i];
  14.             num %= radix[i];
  15.             for (; count > 0; --count) roman += symbol[i];
  16.         }
  17.         return roman;
  18.     }
  19. };

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原文: https://soulmachine.gitbooks.io/algorithm-essentials/content/cpp/string/integer-to-roman.html