leetcode

0 class Solution {

1 public:

2 int findPairs(vector<int> &nums, int k) {

3 int res = 0;

4 if (k == 0) {

5 unordered_map<int, int> um;

6 for (int n : nums)

7 um[n]++;

8 for (const auto &[n, v] : um)

9 res += v >= 2;

10 return res;

11 } else {

12 unordered_set<int> us(nums.begin(), nums.end());

13 for (const auto &n : us)

14 res += us.count(n + k) + us.count(n - k);

15 return res / 2;

16 }

17 }

18 };