add: 220225-CN [cpp]

cpp/2202/220225-CN.cpp

@@ -0,0 +1,31 @@
+#include <complex>
+#include <cstdio>
+#include <string>
+
+/**
+ * 537. Complex Number Multiplication
+ * A complex number can be represented as a string on the form "real+imaginaryi" where:
+ * real is the real part and is an integer in the range [-100, 100].
+ * imaginary is the imaginary part and is an integer in the range [-100, 100].
+ * i2 == -1.
+ * Given two complex numbers num1 and num2 as strings, return a string of the complex number that represents their multiplications.
+ */
+
+class Solution {
+public:
+	static std::string complexNumberMultiply(const std::string& num1, const std::string& num2) {
+		int r1, r2, i1, i2;
+		std::sscanf(num1.c_str(), "%d+%d", &r1, &i1);
+		std::sscanf(num2.c_str(), "%d+%d", &r2, &i2);
+		std::complex<int> c1(r1, i1), c2(r2, i2);
+		auto ans = c1 * c2;
+		char ret[50]{};
+		std::sprintf(ret, "%d+%di", ans.real(), ans.imag());
+		return ret;
+	}
+};
+
+int main() {
+	// too simple to test
+	return 0;
+}

cpp/2202/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2202)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2202 220224.cpp)
+ADD_EXECUTABLE(2202 220225-CN.cpp)