Class Solution


  • public class Solution
    extends Object
    2563 - Count the Number of Fair Pairs.

    Medium

    Given a 0-indexed integer array nums of size n and two integers lower and upper, return the number of fair pairs.

    A pair (i, j) is fair if:

    • 0 <= i < j < n, and
    • lower <= nums[i] + nums[j] <= upper

    Example 1:

    Input: nums = [0,1,7,4,4,5], lower = 3, upper = 6

    Output: 6

    Explanation: There are 6 fair pairs: (0,3), (0,4), (0,5), (1,3), (1,4), and (1,5).

    Example 2:

    Input: nums = [1,7,9,2,5], lower = 11, upper = 11

    Output: 1

    Explanation: There is a single fair pair: (2,3).

    Constraints:

    • 1 <= nums.length <= 105
    • nums.length == n
    • -109 <= nums[i] <= 109
    • -109 <= lower <= upper <= 109
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • countFairPairs

        public long countFairPairs​(int[] nums,
                                   int lower,
                                   int upper)