第一关

public static void main(String[] args) {
        //动态构建arr1
        int[] arr1 = new int[3];
        Scanner sc = new Scanner(System.in);
        for(int i = 0 ; i< arr1.length ; i++){
            arr1[i] = sc.nextInt();
        }
        /********** Begin **********/
        //创建数组arr2
        int[] arr2 = new int[3];
        for (int i = 0; i < arr1.length; i++) {
            arr2[i] = arr1[i];
        }
        //使用for循环将arr1的数据复制给arr2
        //输出arr2
        for (int i = 0; i < arr2.length; i++) {
            System.out.println(arr2[i]);
        }
        /********** End **********/
    }

第二关

public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        //str为要查找的字符串
        String str = sc.next();

        /********** Begin **********/
        //创建数组   arr  给数组赋值 {"张三","张三丰","张无忌","王二麻子","张富贵"}
        String arr[] = new String[]{"张三","张三丰","张无忌","王二麻子","张富贵"};

        for (int i = 0; i < arr.length; i++) {
            if (str.equals(arr[i]))
            {
                System.out.println(str + "在数组的第"+(i+1)+"个位置");
            }
        }
        
        /********** End **********/
	}

第三关

public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		/********** Begin **********/
		//将a的值赋给b   b的值赋给a
		int temp = a;
        a = b;
        b = temp;
		/********** End **********/
		System.out.println(a);
		System.out.println(b);
	}

第四关

选择排序

	   public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        //动态创建数组
        int[] arr = new int[sc.nextInt()];
        for (int i = 0; i < arr.length; i++) {
            arr[i] = sc.nextInt();
        }
        /********** Begin **********/
        int temp =0;
        for (int i = 0; i < arr.length; i++) {
            int min = i;
            for (int j = i; j < arr.length; j++) {
                if (arr[j] >= arr[min]) {
                    min = j;
                    /********** End **********/
                }
            }
            temp = arr[min];
            arr[min] = arr[i];
            arr[i] = temp;
        }
        System.out.println(Arrays.toString(arr));
    }

第五关

冒泡

public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        //动态创建数组
        int[] arr = new int[sc.nextInt()];
        for(int i = 0 ; i< arr.length ; i++){
            arr[i] = sc.nextInt();
        }
        /********** Begin **********/
        for(int i = 0;i<arr.length;i++)
        {
            for (int j = 0; j < arr.length; j++) {
                if (arr[i] < arr[j])
                {
                    int temp = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                }
            }
           
        /********** End **********/
        }
        System.out.println(Arrays.toString(arr));
    }