first commit

J01009 - TỔNG GIAI THỪA.java

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+/*
+ * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
+ * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Main.java to edit this template
+ */
+package test;
+import java.util.Scanner;
+/**
+ *
+ * @author hoang
+ */
+public class Test {
+
+    /**
+     * @param args the command line arguments
+     */
+    public static void main(String[] args) {
+        Scanner reader = new Scanner(System.in);
+        long n = reader.nextLong();
+        long ans = 0;
+        long[] f = new long[22];
+        f[0]=1;
+        for(int i=1; i<=n ; i++){
+            f[i]=f[i-1]*i;
+            ans+=f[i];
+        }
+        System.out.print(ans);
+        reader.close();
+    }
+    
+}