{ "data": { "question": { "questionId": "354", "questionFrontendId": "354", "categoryTitle": "Algorithms", "boundTopicId": 1618, "title": "Russian Doll Envelopes", "titleSlug": "russian-doll-envelopes", "content": "

You are given a 2D array of integers envelopes where envelopes[i] = [wi, hi] represents the width and the height of an envelope.

\n\n

One envelope can fit into another if and only if both the width and height of one envelope are greater than the other envelope's width and height.

\n\n

Return the maximum number of envelopes you can Russian doll (i.e., put one inside the other).

\n\n

Note: You cannot rotate an envelope.

\n\n

 

\n

Example 1:

\n\n
\nInput: envelopes = [[5,4],[6,4],[6,7],[2,3]]\nOutput: 3\nExplanation: The maximum number of envelopes you can Russian doll is 3 ([2,3] => [5,4] => [6,7]).\n
\n\n

Example 2:

\n\n
\nInput: envelopes = [[1,1],[1,1],[1,1]]\nOutput: 1\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "俄罗斯套娃信封问题", "translatedContent": "

给你一个二维整数数组 envelopes ，其中 envelopes[i] = [wi, hi] ，表示第 i 个信封的宽度和高度。

\n\n

当另一个信封的宽度和高度都比这个信封大的时候，这个信封就可以放进另一个信封里，如同俄罗斯套娃一样。

\n\n

请计算 最多能有多少个 信封能组成一组“俄罗斯套娃”信封（即可以把一个信封放到另一个信封里面）。

\n\n

注意：不允许旋转信封。

\n \n\n

示例 1：

\n\n
\n输入：envelopes = [[5,4],[6,4],[6,7],[2,3]]\n输出：3\n解释：最多信封的个数为 3, 组合为: [2,3] => [5,4] => [6,7]。
\n\n

示例 2：

\n\n
\n输入：envelopes = [[1,1],[1,1],[1,1]]\n输出：1\n
\n\n

 

\n\n

提示：

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