{ "data": { "question": { "questionId": "2921", "questionFrontendId": "2801", "categoryTitle": "Algorithms", "boundTopicId": 2362082, "title": "Count Stepping Numbers in Range", "titleSlug": "count-stepping-numbers-in-range", "content": "

Given two positive integers low and high represented as strings, find the count of stepping numbers in the inclusive range [low, high].

\n\n

A stepping number is an integer such that all of its adjacent digits have an absolute difference of exactly 1.

\n\n

Return an integer denoting the count of stepping numbers in the inclusive range [low, high].

\n\n

Since the answer may be very large, return it modulo 109 + 7.

\n\n

Note: A stepping number should not have a leading zero.

\n\n

 

\n

Example 1:

\n\n
\nInput: low = "1", high = "11"\nOutput: 10\nExplanation: The stepping numbers in the range [1,11] are 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. There are a total of 10 stepping numbers in the range. Hence, the output is 10.
\n\n

Example 2:

\n\n
\nInput: low = "90", high = "101"\nOutput: 2\nExplanation: The stepping numbers in the range [90,101] are 98 and 101. There are a total of 2 stepping numbers in the range. Hence, the output is 2.
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "统计范围内的步进数字数目", "translatedContent": "

给你两个正整数 low 和 high ，都用字符串表示，请你统计闭区间 [low, high] 内的 步进数字 数目。

\n\n

如果一个整数相邻数位之间差的绝对值都 恰好 是 1 ，那么这个数字被称为 步进数字 。

\n\n

请你返回一个整数，表示闭区间 [low, high] 之间步进数字的数目。

\n\n

由于答案可能很大，请你将它对 109 + 7 取余 后返回。

\n\n

注意：步进数字不能有前导 0 。

\n\n

 

\n\n

示例 1：

\n\n
输入：low = \"1\", high = \"11\"\n输出：10\n解释：区间 [1,11] 内的步进数字为 1 ，2 ，3 ，4 ，5 ，6 ，7 ，8 ，9 和 10 。总共有 10 个步进数字。所以输出为 10 。
\n\n

示例 2：

\n\n
输入：low = \"90\", high = \"101\"\n输出：2\n解释：区间 [90,101] 内的步进数字为 98 和 101 。总共有 2 个步进数字。所以输出为 2 。
\n\n

 

\n\n

提示：

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