Problem library

Fair Pairs

Medium
greedysortingtwo pointers
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Matchmaking may pair two players only if their ratings differ by at most k. Each player can be in at most one pair.

Return the largest number of pairs that can be formed.

Examples

Input: ratings = [1200,1500,1250,1490], k = 50
Output: 2
Input: ratings = [1000,2000], k = 100
Output: 0