用递归求1!+2!+……+n!，从键盘输入n的值。

以下是Java和C语言两种递归求1!+2!+……+n!的例子，其中n从键盘输入：
1. Java代码：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("请输入一个正整数n：");
        int n = input.nextInt();
        int sum = 0;
        for (int i = 1; i <= n; i++) {
            sum += factorial(i);
        }
        System.out.println("1!+2!+...+n!的和为：" + sum);
    }

    public static int factorial(int n) {
        if (n == 1) {
            return 1;
        } else {
            return n * factorial(n - 1);
        }
    }
}

2. C语言代码：

#include <stdio.h>

int factorial(int n);

int main() {
    int n, sum = 0;
    printf("请输入一个正整数n：");
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) {
        sum += factorial(i);
    }
    printf("1!+2!+...+n!的和为：%d\n", sum);
    return 0;
}

int factorial(int n) {
    if (n == 1) {
        return 1;
    } else {
        return n * factorial(n - 1);
    }
}