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Java-based LeetCode algorithm problem solutions, regularly updated

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package g0501_0600.s0565_array_nesting;

// #Medium #Array #Depth_First_Search #2022_08_10_Time_5_ms_(95.44%)_Space_75.8_MB_(65.97%)

/**
 * 565 - Array Nesting\.
 *
 * Medium
 *
 * 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**.
**/
public class Solution {
    public int arrayNesting(int[] nums) {
        int index;
        int value;
        int maxLen = 0;
        int len;
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] != -1) {
                index = i;
                len = 0;
                while (nums[index] != -1) {
                    value = nums[index];
                    nums[index] = -1;
                    index = value;
                    len++;
                }
                maxLen = Math.max(len, maxLen);
            }
        }
        return maxLen;
    }
}