357. Count Numbers with Unique Digits

LeetCodeMathDynamic ProgrammingBacktrackingOpen on judge ↗

Given an integer n, return the count of all numbers with unique digits, x, where 0 <= x < 10n. Example 1: Input: n = 2 Output: 91 Explanation: The answer should be the total numbers in the range of 0 ≤ x < 100, excluding 11,22,33,44,55,66,77,88,99 Example 2: Input: n = 0 Output: 1 Constraints: - 0 <= n <= 8

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solution.cppC++17

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