Java上的基本递归

public class RecursionExample {
    public static int factorial(int n) {
        // 基本情况
        if (n == 0) {
            return 1;
        }
        // 递归步骤
        return n * factorial(n - 1);
    }

    public static void main(String[] args) {
        int number = 5;
        System.out.println("Factorial of " + number + " is " + factorial(number));
    }
}

import java.util.HashMap;
import java.util.Map;

public class Fibonacci {
    private static Map<Integer, Integer> memo = new HashMap<>();

    public static int fib(int n) {
        if (n <= 1) {
            return n;
        }
        if (!memo.containsKey(n)) {
            memo.put(n, fib(n - 1) + fib(n - 2));
        }
        return memo.get(n);
    }

    public static void main(String[] args) {
        int number = 10;
        System.out.println("Fibonacci of " + number + " is " + fib(number));
    }
}