Class Solution


  • public class Solution
    extends Object
    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
    • 0 <= nums[i] <= 109
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • numSquarefulPerms

        public int numSquarefulPerms​(int[] nums)