From 7d9b13b6b58277b68727fb5582eec24a258282f1 Mon Sep 17 00:00:00 2001
From: Eat-Swap <root@eatswap.org>
Date: Thu, 16 Jun 2022 13:46:44 +0800
Subject: [PATCH] add: 220616-CN

---
 cpp/2206/220616-CN.cpp  | 40 ++++++++++++++++++++++++++++++++++++++++
 cpp/2206/CMakeLists.txt |  2 +-
 2 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 cpp/2206/220616-CN.cpp

diff --git a/cpp/2206/220616-CN.cpp b/cpp/2206/220616-CN.cpp
new file mode 100644
index 0000000..322b53e
--- /dev/null
+++ b/cpp/2206/220616-CN.cpp
@@ -0,0 +1,40 @@
+#include <vector>
+#include <unordered_set>
+#include <unordered_map>
+
+/**
+ * 532. K-diff Pairs in an Array
+ * Given an array of integers nums and an integer k, return the number of unique k-diff pairs in the array.
+ * A k-diff pair is an integer pair (nums[i], nums[j]), where the following are true:
+ * - 0 <= i, j < nums.length
+ * - i != j
+ * - nums[i] - nums[j] == k
+ * Notice that |val| denotes the absolute value of val.
+ *
+ * Refer: 220209.cpp
+ */
+
+class Solution {
+public:
+	static int findPairs(const std::vector<int>& nums, int k) {
+		int ans = 0;
+		if (k) {
+			std::unordered_set<int> s;
+			for (int i : nums) {
+				if (s.count(i))
+					continue;
+				if (s.count(i + k))
+					++ans;
+				if (s.count(i - k))
+					++ans;
+				s.insert(i);
+			}
+		} else {
+			std::unordered_map<int, int> m;
+			for (int i : nums)
+				if (m[i]++ == 1)
+					++ans;
+		}
+		return ans;
+	}
+};
diff --git a/cpp/2206/CMakeLists.txt b/cpp/2206/CMakeLists.txt
index 3c4ac2a..1dc2d09 100644
--- a/cpp/2206/CMakeLists.txt
+++ b/cpp/2206/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2206)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2206 220615-CN.cpp)
+ADD_EXECUTABLE(2206 220616-CN.cpp)