532. K diff Pairs in an Array - cocoder39/coco39_LC GitHub Wiki
class Solution:
def findPairs(self, nums: List[int], k: int) -> int:
visited = set()
res = set()
for num in nums:
if (num-k) in visited:
res.add((num-k, num))
if (num+k) in visited:
res.add((num, num+k))
visited.add(num)
return len(res)