add: 220528 [cpp]

cpp/2205/220528.cpp

@@ -0,0 +1,16 @@
+#include <vector>
+
+/**
+ * 268. Missing Number
+ * Given an array nums containing n distinct numbers in the range [0, n], return the only number in the range that is missing from the array.
+ */
+
+class Solution {
+public:
+	int missingNumber(const std::vector<int>& nums) {
+		int ans = 0;
+		for (int i = 1; i <= nums.size(); ++i)
+			ans ^= i ^ nums[i - 1];
+		return ans;
+	}
+};

cpp/2205/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2205)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2205 220527.cpp)
+ADD_EXECUTABLE(2205 220528.cpp)