Update: Rename folder name to XSMOJ

XSMOJ/求1~n的和.cpp

@@ -0,0 +1,33 @@
+#include <algorithm>
+#include <iostream>
+#include <iomanip>
+#include <cstring>
+#include <cstdio>
+#include <stack>
+#include <ctime>
+#include <cmath>
+#include <queue>
+typedef long long l;
+typedef double d;
+typedef char c;
+int n;
+using namespace std;
+long long wjh(int a){
+	if(a==n){
+		return n;
+	}
+	else{
+		return wjh(a+1)*a;
+	}
+}
+int main(){
+	cin >>n;
+	if(n==0){
+		cout <<1;
+		return 0;
+	}
+	else{
+		cout <<wjh(1);
+	}
+	return 0;
+}