Package g1901_2000.s1995_count_special_quadruplets

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    1995 - Count Special Quadruplets\.

    Easy

    Given a 0-indexed integer array nums, return the number of distinct quadruplets (a, b, c, d) such that:

    • nums[a] + nums[b] + nums[c] == nums[d], and

    • a < b < c < d

    Example 1:

    Input: nums = 1,2,3,6

    Output: 1

    Explanation: The only quadruplet that satisfies the requirement is (0, 1, 2, 3) because 1 + 2 + 3 == 6.

    Example 2:

    Input: nums = 3,3,6,4,5

    Output: 0

    Explanation: There are no such quadruplets in 3,3,6,4,5.

    Example 3:

    Input: nums = 1,1,1,3,5

    Output: 4

    Explanation: The 4 quadruplets that satisfy the requirement are:

    • (0, 1, 2, 3): 1 + 1 + 1 == 3

    • (0, 1, 3, 4): 1 + 1 + 3 == 5

    • (0, 2, 3, 4): 1 + 1 + 3 == 5

    • (1, 2, 3, 4): 1 + 1 + 3 == 5

    Constraints:

    • 4 <= nums.length <= 50

    • 1 <= nums[i] <= 100

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Integer countQuadruplets(IntArray nums)

      • Methods inherited from class java.lang.Object

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