Java 递归的小练习，累加、累乘、斐波那契兔子、文件递归

递归的小练习，

	public static void main(String[] args) {
		System.out.println(sum(10));
		System.out.println(mul(10));
		System.out.println(tu(3));
		getInFo("D:\\");
		
		
	}
	
	//递归累和
	public static int sum(int num) {
		if (num==1) {
			return 1;
		}else {
			return sum(num-1)+num;
		}
	}
	
	
	//递归累乘
	public static int mul(int num) {
		if (num==1) {
			return 1;
		}else {
			return mul(num-1)*num;
		}
	}
	
	//斐波那契兔子递归
	public static int  tu(int num) {
		if (num==1 || num ==2) {
			return 1;
		}else {
			return tu(num-1)+tu(num-2);
		}
	}
	
	//递归遍历输出xx文件夹内的文件的绝对路径
	public static void getInFo(String path) {
		File myfile = new File(path);
		File[] files = myfile.listFiles();
		for (File file : files) {
			if (file.isFile()) {
				System.out.println(file.getAbsolutePath());
			}else {
				System.out.println(file.getAbsolutePath());
				getInFo(file.getAbsolutePath());
			}
		}
	}