add: 220206-CN

2202/220206-CN.cpp

@@ -0,0 +1,32 @@
+#include <vector>
+#include <unordered_set>
+
+/**
+ * 1748. Sum of Unique Elements
+ * You are given an integer array nums. The unique elements of an array are the elements that appear exactly once in the array.
+ * Return the sum of all the unique elements of nums.
+ */
+
+class Solution {
+public:
+	static int sumOfUnique(const std::vector<int>& nums) {
+		int ans = 0;
+		std::unordered_multiset<int> s;
+		for (int x : nums) {
+			switch (s.count(x)) {
+				case 0:
+					ans += x;
+					break;
+				case 1:
+					ans -= x;
+			}
+			s.insert(x);
+		}
+		return ans;
+	}
+};
+
+int main() {
+	// No testing code.
+	return 0;
+}

2202/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2202)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2202 220205.cpp)
+ADD_EXECUTABLE(2202 220206-CN.cpp)