Package g2501_2600.s2501_longest_square_streak_in_an_array

Class Solution

java.lang.Object
g2501_2600.s2501_longest_square_streak_in_an_array.Solution
public class Solution extends java.lang.Object
2501 - Longest Square Streak in an Array.

Medium

You are given an integer array nums. A subsequence of nums is called a square streak if:

  • The length of the subsequence is at least 2, and
  • after sorting the subsequence, each element (except the first element) is the square of the previous number.

Return the length of the longest square streak in nums, or return -1 if there is no square streak.

A subsequence is an array that can be derived from another array by deleting some or no elements without changing the order of the remaining elements.

Example 1:

Input: nums = [4,3,6,16,8,2]

Output: 3

Explanation: Choose the subsequence [4,16,2]. After sorting it, it becomes [2,4,16].

  • 4 = 2 * 2.

  • 16 = 4 * 4.

Therefore, [4,16,2] is a square streak.

It can be shown that every subsequence of length 4 is not a square streak.

Example 2:

Input: nums = [2,3,5,6,7]

Output: -1

Explanation: There is no square streak in nums so return -1.

Constraints:

  • 2 <= nums.length <= 105
  • 2 <= nums[i] <= 105

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    longestSquareStreak(int[] nums)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • longestSquareStreak

      public int longestSquareStreak(int[] nums)