题目解析
计算 1 到 指定数字的 所有阶层 的总和
解题思路
利用性质直接暴力求值
代码
import java.io.*;
import java.util.*;
public class Main
{
static int jieceng(int n)
{
int mul = 1;
for (int i = 1; i <= n; i++)
mul = mul * i;
return mul;
}
public static void main(String[] args)
{
int n = sc.nextInt();
int ans = 0;
for (int i = 1; i <= n; i++)
ans += jieceng(i);
out.println(ans);
out.flush();
out.close();
}
static Scanner sc = new Scanner(System.in);
static PrintWriter out = new PrintWriter(System.out);
}