{ "data": { "question": { "questionId": "357", "questionFrontendId": "357", "categoryTitle": "Algorithms", "boundTopicId": 1690, "title": "Count Numbers with Unique Digits", "titleSlug": "count-numbers-with-unique-digits", "content": "

Given an integer n, return the count of all numbers with unique digits, x, where 0 <= x < 10n.

\n\n

 

\n

Example 1:

\n\n
\nInput: n = 2\nOutput: 91\nExplanation: The answer should be the total numbers in the range of 0 ≤ x < 100, excluding 11,22,33,44,55,66,77,88,99\n
\n\n

Example 2:

\n\n
\nInput: n = 0\nOutput: 1\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "统计各位数字都不同的数字个数", "translatedContent": "给你一个整数 n ，统计并返回各位数字都不同的数字 x 的个数，其中 0 <= x < 10n 。\n
\n
\n

 

\n\n

示例 1：

\n\n
\n输入：n = 2\n输出：91\n解释：答案应为除去 11、22、33、44、55、66、77、88、99 外，在 0 ≤ x < 100 范围内的所有数字。 \n
\n\n

示例 2：

\n\n
\n输入：n = 0\n输出：1\n
\n
\n
\n\n

 

\n\n

提示：

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