package array; import java.util.HashMap; import java.util.Map; /** * @ProjectName: leetcode * @Package: array * @ClassName: Array532 * @Author: markey * @Description: * @Date: 2020/2/8 23:06 * @Version: 1.0 */ public class Array532 { public int findPairs(int[] nums, int k) { if (k < 0) { return 0; } Map map = new HashMap<>(); for (int i: nums) { map.put(i, map.getOrDefault(i, 0) + 1); } int res = 0; for (int key: map.keySet()) { if (k == 0) { res += map.get(key) / 2; } else { if (map.containsKey(key + k)) { int min = Math.min(map.get(key), map.get(key + k)); res += min; map.put(key, map.get(key) - min); } } } return res; } }