Class Solution

  • All Implemented Interfaces:

    
    public final class Solution
    
                        

    996 - Number of Squareful Arrays.

    Hard

    An array is squareful if the sum of every pair of adjacent elements is a perfect square.

    Given an integer array nums, return the number of permutations of nums that are squareful.

    Two permutations perm1 and perm2 are different if there is some index i such that perm1[i] != perm2[i].

    Example 1:

    Input: nums = 1,17,8

    Output: 2

    Explanation: 1,8,17 and 17,8,1 are the valid permutations.

    Example 2:

    Input: nums = 2,2,2

    Output: 1

    Constraints:

    • 1 <= nums.length <= 12

    • <code>0 <= numsi<= 10<sup>9</sup></code>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private Integer count
    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()
    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description