course（递归专题）求累加和

1659_n!/main.cpp

@@ -5,7 +5,7 @@ long long dg(long long n){
     if(n==1){
         return 1;
     }
-    return n+dg(n-1);
+    return n*dg(n-1);
 }
 int main()
 {

1659_n!/test/out.txt

@@ -1,18 +1,18 @@
 ## z:\Chao\src\1659_n!\test\in.txt 
-2020/04/24 周五 13:42:16.59 
+2020/04/24 周五 13:46:26.28 
 1
 -----------------------------------------------
-Process exited after 190 ms with return value 0
+Process exited after 140 ms with return value 0
 
 ## z:\Chao\src\1659_n!\test\in2.txt 
-2020/04/24 周五 13:42:16.59 
+2020/04/24 周五 13:46:26.28 
 1307674368000
 -----------------------------------------------
-Process exited after 100 ms with return value 0
+Process exited after 90 ms with return value 0
 
 ## z:\Chao\src\1659_n!\test\in3.txt 
-2020/04/24 周五 13:42:16.59 
+2020/04/24 周五 13:46:26.28 
 24
 -----------------------------------------------
-Process exited after 110 ms with return value 0
+Process exited after 180 ms with return value 0
 

1660_n+/Readme.md

@@ -0,0 +1,3 @@
+# 标题
+
+* 内容

1660_n+/doc/Readme.md

@@ -0,0 +1,18 @@
+# 		『入门』（递归专题）求累加和
+[问题描述]  
+
+教学案例，必须使用递归函数完成求解！  
+
+　　编程求解下列式子的值：s=1+2+3+...+n。  
+
+[输入格式]  
+　　一行，只有一个整数n。(1 <= n <= 1000)  
+
+[输出格式]  
+　　1个整数，即s的值。  
+
+[输入样例]  
+100  
+
+[输出样例]  
+5050  

1660_n+/main.cpp

@@ -0,0 +1,15 @@
+//½×¼Ó£¨³¬Ð¡£©
+#include <iostream>
+using namespace std;
+long long dg(long long n){
+    if(n==1){
+        return 1;
+    }
+    return n+dg(n-1);
+}
+int main()
+{
+    int n;
+    cin>>n;
+    cout<<dg(n);
+}

1660_n+/test/in.txt

@@ -0,0 +1 @@
+1

1660_n+/test/in2.txt

@@ -0,0 +1 @@
+100

1660_n+/test/in3.txt

@@ -0,0 +1 @@
+1000

1660_n+/test/out.txt

@@ -0,0 +1,18 @@
+## z:\Chao\src\1660_n+\test\in.txt 
+2020/04/24 周五 13:47:20.56 
+1
+-----------------------------------------------
+Process exited after 160 ms with return value 0
+
+## z:\Chao\src\1660_n+\test\in2.txt 
+2020/04/24 周五 13:47:20.56 
+5050
+-----------------------------------------------
+Process exited after 80 ms with return value 0
+
+## z:\Chao\src\1660_n+\test\in3.txt 
+2020/04/24 周五 13:47:20.56 
+500500
+-----------------------------------------------
+Process exited after 80 ms with return value 0
+