565. Array Nesting
Description
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 should build a set s[k] = {nums[k], nums[nums[k]], nums[nums[nums[k]]], ... }
subjected to the following rule:
- The first element in
s[k]
starts with the selection of the elementnums[k]
ofindex = k
. - The next element in
s[k]
should benums[nums[k]]
, and thennums[nums[nums[k]]]
, and so on. - We stop adding right before a duplicate element occurs in
s[k]
.
Return the longest length of a set s[k]
.
Example 1:
Input: nums = [5,4,0,3,1,6,2] Output: 4 Explanation: nums[0] = 5, nums[1] = 4, nums[2] = 0, nums[3] = 3, nums[4] = 1, nums[5] = 6, nums[6] = 2. One of the longest sets s[k]: s[0] = {nums[0], nums[5], nums[6], nums[2]} = {5, 6, 2, 0}
Example 2:
Input: nums = [0,1,2] Output: 1
Constraints:
1 <= nums.length <= 105
0 <= nums[i] < nums.length
- All the values of
nums
are unique.
Solutions
Solution 1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 |
|
Solution 2
1 2 3 4 5 6 7 8 9 10 11 12 |
|