leetcode-algorithms/src/KDiffPairsInAnArray.java at master · anishLearnsToCode/leetcode-algorithms · GitHub

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import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

public class KDiffPairsInAnArray {

public int findPairs(int[] nums, int k) {

int pairs= 0;

if (k == 0) {

Map<Integer, Integer> frequencies = new HashMap<>();

for (int number : nums) {

frequencies.put(number, frequencies.getOrDefault(number, 0) + 1);

}

for (int frequency : frequencies.values()) {

pairs += frequency > 1 ? 1 : 0;

}

} else {

Set<Integer> numbers = new HashSet<>();

for (int number : nums) {

if (!numbers.contains(number)) {

pairs += numbers.contains(number - k) ? 1 : 0;

pairs += numbers.contains(number + k) ? 1 : 0;

numbers.add(number);

}

return pairs;

}

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