JAVA经典之递归测试-----JAVA入门基础教程

public class Test
{
    public static void main(String[] args)
    {
        Test a = new Test();
        System.out.println(a.getSum(100));
        System.out.println(a.getSum1(100));
        System.out.println(a.getMul(5));
        System.out.println(a.f(10));
    }
    public int getSum(int num)
    {
        int sum = 0;
        for (int i = 0; i <= num; i++)
        {
            sum = sum + i;
        }
        return sum;
    }
    public int getSum1(int num)
    {
        if(num == 1)
        {
            return 1;
        }
        else
        {
            return getSum1(num-1) + num;
        }
    }
    public int getMul(int n)
    {
        if(n == 1)
        {
            return 1;
        }
        else
        {
            return n * getMul(n -  1);
        }
    }
    public int f(int n)
    {
        if(n == 1)
        {
            return 1;
        }
        else if(n == 2)
        {
            return 1;
        }
        else
        {
            return f(n - 1) + f(n - 2);
        }
    }
}