Update CMakeLists.txt

_others/qyz/gdbh.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+
+using namespace std;
+
+int primes[2001];
+
+bool is_prime(int a) {
+    for (int i = 2; i * i <= a; i++) {
+        if (a % i != 0) {
+            continue;
+        } else {
+            return false;
+        }
+    }
+    return true;
+}
+
+void init_primes() {
+    int current_num = 2, i = 0;
+    for (;; current_num++) {
+        if (is_prime(current_num)) {
+            primes[i] = current_num;
+            i++;
+        }
+    }
+}
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+    int a;
+    cin >> a;
+    if (a % 2 != 0 || a < 6) {
+        cout << "Error!" << endl;
+    } else
+        for (int i = 0; primes[i] <= a / 2; i++) {
+            if (is_prime(a - primes[i])) {
+                cout << a << "=" << i << "+" << a - i << endl;
+            }
+        }
+
+    return 0;
+}

_others/qyz/test.cpp

@@ -0,0 +1,18 @@
+#include <iostream>
+
+using namespace std;
+
+
+// x[0]..x[99]
+
+bool is_prime(int n) {
+    for (int i=2; i*i<=n; i++) {
+        if (n%i == 0) {return false;}
+    }
+    return true;
+}
+
+int main() {
+    cout << is_prime(4);
+    return 0;
+}