C#基础练习

1、冒泡排序

namespace _0
{
    class Program
    {
        public static int[] BubbleSort(int[] arr)
        {
            for (int i = 0; i < arr.Length - 1; i++)
            {
                for (int j = 0; j < arr.Length - 1; j++)
                {
                    if (arr[j] > arr[j + 1])
                    {
                        int temp = arr[j];
                        arr[j] = arr[j + 1];
                        arr[j + 1] = temp;
                    }
                }
            }
            return arr;
        }
        static void Main(string[] args)
        {
            int[] numbers = { 2, 5, -7, 9, 3, 2, 1, -3, 0, 2 };
            int[] result = BubbleSort(numbers);
            for (int i = 0; i < result.Length; i++)
            {
                Console.Write("{0} ", result[i]);
            }
            Console.ReadKey();
        }
    }
}

2、100~999之间的水仙花数

namespace _0
{
    class Program
    {
        public static bool Daffodils(int arr)
        {
            int hundreds = arr / 100;  // 获取百位数
            int ten = arr / 10 % 10;  // 获取十位数
            int single = arr % 10;  // 获取个位数
            int n = (hundreds * hundreds * hundreds) + 
                    (ten * ten * ten) + 
                    (single * single * single);
            if (arr == n)
            {
                return true;
            }
            return false;
        }
        static void Main(string[] args)
        {
            for (int i = 100; i < 999; i++)
            {
                bool flag = Daffodils(i);
                if (flag)
                {
                    Console.WriteLine("Daffodils: {0}", i);
                }
            }
            Console.ReadKey();
        }
    }
}

3、取出数组中最大值和最小值

namespace _0
{
    class Program
    {
        public static int[] ReturnMaxAndMin(int[] arr)
        {
            int[] result = { arr[0], arr[0] };
            for (int i = 0; i < arr.Length; i++)
            {
                if (arr[i] > result[0])
                {
                    result[0] = arr[i];
                }
                else if (arr[i] < result[1])
                {
                    result[1] = arr[i];
                }
            }
            return result;
        }
        static void Main(string[] args)
        {
            int[] arrary = { 1, 2, 4, 6, 7, 8, -1, 2, -4 };
            int[] numbers = ReturnMaxAndMin(arrary);
            Console.WriteLine("Max number: {0}, Min number: {1}", numbers[0], numbers[1]);
            Console.ReadKey();
        }
    }
}