{ "data": { "question": { "questionId": "12", "questionFrontendId": "12", "categoryTitle": "Algorithms", "boundTopicId": 1193, "title": "Integer to Roman", "titleSlug": "integer-to-roman", "content": "
Roman numerals are represented by seven different symbols: I
, V
, X
, L
, C
, D
and M
.
\nSymbol Value\nI 1\nV 5\nX 10\nL 50\nC 100\nD 500\nM 1000\n\n
For example, 2
is written as II
in Roman numeral, just two one's added together. 12
is written as XII
, which is simply X + II
. The number 27
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.
\n\n\n
Example 1:
\n\n\nInput: num = 3\nOutput: "III"\nExplanation: 3 is represented as 3 ones.\n\n\n
Example 2:
\n\n\nInput: num = 58\nOutput: "LVIII"\nExplanation: L = 50, V = 5, III = 3.\n\n\n
Example 3:
\n\n\nInput: num = 1994\nOutput: "MCMXCIV"\nExplanation: M = 1000, CM = 900, XC = 90 and IV = 4.\n\n\n
\n
Constraints:
\n\n1 <= num <= 3999
罗马数字包含以下七种字符: I
, V
, X
, L
,C
,D
和 M
。
\n字符 数值\nI 1\nV 5\nX 10\nL 50\nC 100\nD 500\nM 1000\n\n
例如, 罗马数字 2 写做 II
,即为两个并列的 1。12 写做 XII
,即为 X
+ II
。 27 写做 XXVII
, 即为 XX
+ V
+ II
。
通常情况下,罗马数字中小的数字在大的数字的右边。但也存在特例,例如 4 不写做 IIII
,而是 IV
。数字 1 在数字 5 的左边,所表示的数等于大数 5 减小数 1 得到的数值 4 。同样地,数字 9 表示为 IX
。这个特殊的规则只适用于以下六种情况:
I
可以放在 V
(5) 和 X
(10) 的左边,来表示 4 和 9。X
可以放在 L
(50) 和 C
(100) 的左边,来表示 40 和 90。 C
可以放在 D
(500) 和 M
(1000) 的左边,来表示 400 和 900。给你一个整数,将其转为罗马数字。
\n\n\n\n
示例 1:
\n\n\n输入: num = 3\n输出: \"III\"\n\n
示例 2:
\n\n\n输入: num = 4\n输出: \"IV\"\n\n
示例 3:
\n\n\n输入: num = 9\n输出: \"IX\"\n\n
示例 4:
\n\n\n输入: num = 58\n输出: \"LVIII\"\n解释: L = 50, V = 5, III = 3.\n\n\n
示例 5:
\n\n\n输入: num = 1994\n输出: \"MCMXCIV\"\n解释: M = 1000, CM = 900, XC = 90, IV = 4.\n\n
\n\n
提示:
\n\n1 <= num <= 3999
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use-after-free<\\/code>\\u9519\\u8bef\\u3002<\\/p>\\r\\n\\r\\n
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