用递归方法算S=1+2+3+…+n

以下是两种语言的递归方法求解S=1+2+3+...+n的和：

- C++代码：

#include <iostream>
using namespace std;

int funSum(int n) {
    if(n == 1) return 1;
    else return n + funSum(n-1);
}

int main() {
    int n, sum;
    cout << "input n: ";
    cin >> n;
    sum = funSum(n);
    cout << "the sum is: " << sum << endl;
    return 0;
}

- Java代码：

public class Sum {
    public static int funSum(int n) {
        if(n == 1) return 1;
        else return n + funSum(n-1);
    }

    public static void main(String[] args) {
        int n = 10;
        int sum = funSum(n);
        System.out.println("the sum is: " + sum);
    }
}