递归

递：传递

归：回归（return

import org.junit.Test;

public class Digui {

    @Test
    public void diguiTest() {
        System.out.println(f(2));
    }

    public int f(int n) {
        // 归
        if (n == 1)
            return 1;
        // 递
        return n * f(n - 1);
    }

}