leetcode-daily

Array Nesting

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 element nums[k] of index = k.

The next element in s[k] should be nums[nums[k]], and then nums[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.