819. 递归求阶乘

https://www.acwing.com/problem/content/submission/code_detail/14063914/

AcWing/819/819.cpp

@@ -0,0 +1,20 @@
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+int f(int x) {
+    return x == 1 ? 1 : x * f(x - 1);
+}
+
+int n;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+
+    cin >> n;
+    cout << f(n) << endl;
+
+    return 0;
+}