#13340. 「NOIP2022模拟赛1111」摆放石子

http://www.nfls.com.cn:10611/submission/238467

NFLSOJ/13340/13340.cpp

@@ -0,0 +1,74 @@
+// #include <iostream>
+#include <fstream>
+
+// using std::cin;
+// using std::cout;
+std::ifstream cin("stone.in");
+std::ofstream cout("stone.out");
+const char endl = '\n';
+
+int n;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    if (n == 1) {
+        cout << "YES" << endl
+             << 1 << ' ' << 1 << endl;
+    } else if (n % 4 == 0) {
+        int k = n / 4;
+
+        cout << "YES" << endl;
+
+        for (int i = 1; i <= k; i++) {
+            cout << i << ' ' << n - i + 1 << endl;
+        }
+
+        for (int i = k + 1; i <= 2 * k - 1; i++) {
+            cout << i << ' ' << n - i << endl;
+        }
+
+        cout << 2 * k << ' ' << 1 << endl;
+
+        for (int i = 2 * k + 1; i <= 3 * k - 1; i++) {
+            cout << i << ' ' << n - i + 1 << endl;
+        }
+
+        cout << 3 * k << ' ' << n - k << endl;
+
+        for (int i = 3 * k + 1; i <= 4 * k; i++) {
+            cout << i << ' ' << n - i + 2 << endl;
+        }
+    } else if (n % 4 == 1) {
+        int k = n / 4;
+
+        cout << "YES" << endl;
+
+        for (int i = 1; i <= k; i++) {
+            cout << i << ' ' << n - i + 1 << endl;
+        }
+
+        cout << k + 1 << ' ' << k + 2 << endl;
+
+        for (int i = k + 2; i <= 2 * k; i++) {
+            cout << i << ' ' << n - i + 2 << endl;
+        }
+
+        cout << 2 * k + 1 << ' ' << 1 << endl;
+
+        for (int i = 2 * k + 2; i <= 3 * k + 1; i++) {
+            cout << i << ' ' << n - i + 3 << endl;
+        }
+
+        for (int i = 3 * k + 2; i <= 4 * k + 1; i++) {
+            cout << i << ' ' << n - i + 2 << endl;
+        }
+    } else {
+        cout << "NO" << endl;
+    }
+
+    return 0;
+}