'commit'

TangDou/LuoGuBook/第8章模拟与高精度/P1009_Study.cpp

@@ -0,0 +1,18 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    int n;
+    cin >> n; // n!+(n-1)!+(n-2)!+...+1!
+
+    int sum = 0;                   //结果，累加和
+    for (int i = n; i >= 1; i--) { //枚举 n,n-1,n-2,....,1
+        //计算n这个数字的阶乘
+        int res = 1;
+        for (int j = i; j >= 1; j--) res *= j;
+        sum += res;
+    }
+    cout << sum << endl;
+    return 0;
+}