'commit'

TangDou/Mkx/CuoPaiGongShi.cpp

@@ -0,0 +1,13 @@
+#include <iostream>
+using namespace std;
+typedef long long LL;
+
+int main() {
+    LL f[21] = {0, 0, 1}; //这个初始化很牛B的样子,放过头雁打二雁，而且f[1]=0,f[2]=1
+    //错排公式,预处理
+    for (int i = 3; i < 21; i++) f[i] = (i - 1) * (f[i - 1] + f[i - 2]);
+
+    for (int i = 1; i <= 20; i++)
+        cout << "i=" << i << ",f[" << i << "]=" << f[i] << endl;
+    return 0;
+}