Maximum K to Sort a Permutation
You are given an integer array nums of length n, where nums is a permutation of the numbers in the range [0..n - 1].
You may swap elements at indices i and j only if nums[i] AND nums[j] == k, where AND denotes the bitwise AND operation and k is a non-negative integer.
Return the maximum value of k such that the array can be sorted in non-decreasing order using any number of such swaps. If nums is already sorted, return 0.
Example 1
Input
nums = [0,3,2,1]Output
1Choose
k = 1; swapping nums[1] = 3 and nums[3] = 1 is allowed since nums[1] AND nums[3] == 1, resulting in [0, 1, 2, 3].Example 2
Input
nums = [0,1,3,2]Output
2Choose
k = 2; swapping nums[2] = 3 and nums[3] = 2 is allowed since nums[2] AND nums[3] == 2, resulting in [0, 1, 2, 3].Constraints
- 1 <= n == nums.length <= 10^5
- 0 <= nums[i] <= n - 1
- nums is a permutation of integers from 0 to n - 1.