add: 220328-CN [cpp]

cpp/2203/220328-CN.cpp

@@ -0,0 +1,19 @@
+#include <iostream>
+
+/**
+ * 693. Binary Number with Alternating Bits
+ * Given a positive integer, check whether it has alternating bits: namely, if two adjacent bits will always have different values.
+ */
+
+class Solution {
+public:
+	static constexpr bool hasAlternatingBits(int n) {
+		unsigned x = unsigned(1 << (32 - __builtin_clz(n))) - 1;
+		return ((n ^ 0x55555555) & x) == x || ((n ^ 0xAAAAAAAA) & x) == x;
+	}
+};
+
+int main() {
+	std::printf("%s", Solution::hasAlternatingBits(33) ? "true" : "false");
+	return 0;
+}

cpp/2203/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2203)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2203 220327-CN.cpp)
+ADD_EXECUTABLE(2203 220328-CN.cpp)