{ "data": { "question": { "questionId": "2202", "questionFrontendId": "2081", "boundTopicId": null, "title": "Sum of k-Mirror Numbers", "titleSlug": "sum-of-k-mirror-numbers", "content": "

A k-mirror number is a positive integer without leading zeros that reads the same both forward and backward in base-10 as well as in base-k.

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Given the base k and the number n, return the sum of the n smallest k-mirror numbers.

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Example 1:

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\nInput: k = 2, n = 5\nOutput: 25\nExplanation:\nThe 5 smallest 2-mirror numbers and their representations in base-2 are listed as follows:\n  base-10    base-2\n    1          1\n    3          11\n    5          101\n    7          111\n    9          1001\nTheir sum = 1 + 3 + 5 + 7 + 9 = 25. \n
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Example 2:

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\nInput: k = 3, n = 7\nOutput: 499\nExplanation:\nThe 7 smallest 3-mirror numbers are and their representations in base-3 are listed as follows:\n  base-10    base-3\n    1          1\n    2          2\n    4          11\n    8          22\n    121        11111\n    151        12121\n    212        21212\nTheir sum = 1 + 2 + 4 + 8 + 121 + 151 + 212 = 499.\n
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Example 3:

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\nInput: k = 7, n = 17\nOutput: 20379000\nExplanation: The 17 smallest 7-mirror numbers are:\n1, 2, 3, 4, 5, 6, 8, 121, 171, 242, 292, 16561, 65656, 2137312, 4602064, 6597956, 6958596\n
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Constraints:

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