add: 220221 [cpp]

cpp/2202/220221.cpp

@@ -0,0 +1,24 @@
+#include <vector>
+#include <unordered_map>
+
+/**
+ * 169. Majority Element
+ * Given an array nums of size n, return the majority element.
+ * The majority element is the element that appears more than ⌊n / 2⌋ times. You may assume that the majority element always exists in the array.
+ */
+
+class Solution {
+public:
+	static inline int majorityElement(const std::vector<int>& nums) {
+		int n = nums.size() >> 1;
+		std::unordered_map<int, int> m;
+		for (int i : nums)
+			if (++m[i] > n)
+				return i;
+		return 0;
+	}
+};
+
+int main() {
+	return 0;
+}

cpp/2202/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2202)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2202 220221-CN.cpp)
+ADD_EXECUTABLE(2202 220221.cpp)