'commit'

TangDou/XiTi/1143.cpp

@@ -0,0 +1,26 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+
+//判断是不是质数
+bool isPrime(int n) { //最快的方法
+    if (n < 2) return false;
+    if (n == 2 || n == 3) return true;
+    if (n % 6 != 1 && n % 6 != 5) return false;
+    for (int i = 5; i <= floor(sqrt(n)); i += 6)
+        if (n % i == 0 || n % (i + 2) == 0)
+            return false;
+    return true;
+}
+
+int main() {
+    int n;
+    cin >> n;
+    for (int i = 2; i <= n - 2; ++i) {
+        if (isPrime(i) && isPrime(i + 2)) {
+            cout << i << " " << i + 2 << endl;
+        }
+    }
+    return 0;
+}