[3]565. Array Nesting(Java)

A zero-indexed array A consisting of N different integers is given. The array contains all integers in the range [0, N - 1].

Sets S[K] for 0 <= K < N are defined as follows:

S[K] = { A[K], A[A[K]], A[A[A[K]]], … }.

Sets S[K] are finite for each K and should NOT contain duplicates.

Write a function that given an array A consisting of N integers, return the size of the largest set S[K] for this array.

Example 1:

Input: A = [5,4,0,3,1,6,2]Output: 4Explanation: A[0] = 5, A[1] = 4, A[2] = 0, A[3] = 3, A[4] = 1, A[5] = 6, A[6] = 2.One of the longest S[K]:S[0] = {A[0], A[5], A[6], A[2]} = {5, 6, 2, 0}

Note:

1、 N is an integer within the range [1, 20,000].2、 The elements of A are all distinct.3、 Each element of array A is an integer within the range [0, N-1].

class Solution {    public int arrayNesting(int[] nums) {        int max = 0;        for (int i = 0; i < nums.length; i ++) {            int tmp = 0;            for (int j = i; nums[j] >= 0; tmp ++) {                int p = j;                j = nums[j];                nums[p] = -1;            }            max = Math.max(max, tmp);            }        return max;    }}