{leetcode}/problems/special-permutations/[LeetCode - 2741. Special Permutations ^]
You are given a 0-indexed integer array nums containing n distinct positive integers. A permutation of nums is called special if:
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For all indexes
0 ⇐ i < n - 1, eithernums[i] % nums[i+1] == 0ornums[i+1] % nums[i] == 0.
Return _the total number of special permutations. _As the answer could be large, return it *modulo *10^9 ^+ 7.
Example 1:
Input: nums = [2,3,6] Output: 2 Explanation: [3,6,2] and [2,6,3] are the two special permutations of nums.
Example 2:
Input: nums = [1,4,3] Output: 2 Explanation: [3,1,4] and [4,1,3] are the two special permutations of nums.
Constraints:
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2 ⇐ nums.length ⇐ 14 -
1 ⇐ nums[i] ⇐ 109