Leetcode - Array Nesting

https://leetcode.com/problems/array-nesting

A zero-indexed array A of length N contains all integers from 0 to N-1. Find and return the longest length of set S, where S[i] = {A[i], A[A[i]], A[A[A[i]]], ... } subjected to the rule below.

Suppose the first element in S starts with the selection of element A[i] of index = i, the next element in S should be A[A[i]], and then A[A[A[i]]]… By that analogy, we stop adding right before a duplicate element occurs in S.

Example 1:

Input: A = [5,4,0,3,1,6,2]
Output: 4
Explanation: 
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}

func arrayNesting(nums []int) int {
    result := 0
    for i := 0; i < len(nums); i++ {
        size := 0
        for k := i; nums[k] >= 0; size++ {
            tmp := nums[k]
            nums[k] = -1
            k = tmp
        }
        result = max(result, size)
    }
    return result
}

func max(a, b int) int {
    if a > b {
        return a
    }
    
    return b
}

Time complexity: O(n)

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