面试题对平时编程习惯的考验

       /// <summary>
        /// 获得不重复的随机数数组
        /// </summary>
        /// <param name="min">取值范围:开始值</param>
        /// <param name="max">取值范围:结束值</param>
        /// <param name="count">数组大小</param>
        /// <returns></returns>
        public static int[] GetRandomDistinctIntArray(int minValue, int maxValue, int count)
        {

            int length = (maxValue - minValue) + 1; //取值个数

            #region 参数验证
            if (minValue <= 0 || maxValue < 2)
            {
                throw new ArgumentException("输入开始值大于0且结束值大于1！");
            }

            if ((maxValue - minValue) <= 0)
            {
                throw new ArgumentException("输入开始值和结束值之间的取值个数应大于1！");
            }

            if (minValue > maxValue)
            {
                throw new ArgumentException("输入开始值必须小于结束值！");
            }

            if (count > length)
            {
                throw new ArgumentException("数组大小必须小于或等于取值个数！");
            }
            #endregion

            int[] intList = new int[length];   //临时数组

            for (int i = 0; i < length; i++)   //初始化一个顺序数组 
            {
                intList[i] = i + minValue;
            }

            int[] intRet = new int[count]; //用于存储结果的数组  

            int n = length;

            Random rand = new Random();

            #region 交换元素

            for (int i = 0; i < count; i++)  //交换元素
            {

                int randomNumber = rand.Next(minValue, maxValue + 1);

                int index = randomNumber - minValue;  //索引值
            
                intRet[i] = intList[index];         //把当前随机数的值放在存储结果的数组里  
                intList[index] = intList[--n];     //将当前随机数放到临时数组的最后面
            
                maxValue--;                        //缩小取值范围
            }


            #endregion

            return intRet;
        }

  /// <summary>
        /// 查找指定出现次数的第一个字符
        /// </summary>
        /// <param name="str">需要查找的字符</param>
        /// <param name="charFindCount">查找次数</param>
        /// <returns></returns> 
        public static string FindFirstCountChar(string str, uint charFindCount)
        {
            if (str == null || str == string.Empty)
            {
                throw new ArgumentException("请输入需要查找的字符！");
            }
            if (charFindCount<1)
            {
                throw new ArgumentException("查找字符出现的次数应大于0！");
            }

            int count = 0;  //字符出现的次数

            for (int i = 0; i < str.Length; i++)
            {
                char currentChar = str[i];   //需要查找的字符

                for (int j = 0; j < str.Length; j++)  //在string数组中循环查找
                {
                    if (currentChar == str[j])
                    {
                        count += 1;
                    }
                }

                if (count == charFindCount)
                {
                    return currentChar.ToString();
                }
                count = 0;
            }
            return null;
        }

    /// <summary>
        /// int数组排序
        /// </summary>
        /// <param name="array">需要排序的int集合</param>
        /// <param name="sortOrder">排序规则：true 升序，false降序</param>
        public static int[] IntArraySort(int[] array, bool isSortAsc)
        {
            if (array == null || array.Length < 2)
            {
                throw new ArgumentException("数组必须不为空且数组长度大于2否则无法排序！");
            }
            int temp;  //临时变量，保存最大,小值
            for (int j = 0; j < array.Length; j++)
            {
                for (int i = 0; i < array.Length - j - 1; i++)
                {
                    if (isSortAsc)
                    {
                        #region 升序开始交换
                        if (array[i] > array[i + 1])  // 如果 array[i] > array[i+1] ，则 array[i] 上浮一位,为升序，否则下浮一位为降序
                        {
                            temp = array[i];            //开始交换
                            array[i] = array[i + 1];
                            array[i + 1] = temp;
                        }
                        #endregion
                    }
                    else
                    {
                        #region 降序开始交换
                        if (array[i] < array[i + 1])
                        {
                            temp = array[i];
                            array[i] = array[i + 1];
                            array[i + 1] = temp;
                        }
                        #endregion
                    }
                }
            }
            return array;
        }

      /// <summary>
        /// 打印输出
        /// </summary>
        private static void OutPrint()
        {
            #region 随机数组打印
            try
            {
                int[] intArray = GetRandomDistinctIntArray(1, 15, 5);

                if (intArray == null || intArray.Length <= 0)
                {

                    Console.WriteLine("生成随机数组失败!");
                }
                else
                {
                    foreach (var item in intArray)
                    {

                        Console.Write(item + ",");
                    }
                }
            }
            catch (Exception ex)
            {

                Console.WriteLine(ex.Message);
            }

            #endregion

            #region 数组排序打印

            try
            {
                //int[] intInputArray = new int[] { 5 };
                //int[] intOutArray = IntArraySort(intInputArray, false);

                //if (intOutArray == null || intOutArray.Length <= 0)
                //{
                //    Console.WriteLine("数组排序失败!");
                //}
                //else
                //{
                //    foreach (var item in intOutArray)
                //    {
                //        Console.Write(item + ",");
                //    }
                //}

            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            #endregion

            #region 查找字符打印
            //try
            //{
            //    string str = FindFirstCountChar("abbcbcc",0);
            //    if (str == null || str == string.Empty)
            //    {
            //        Console.Write("无法找到");
            //    }
            //    else
            //    {
            //        Console.Write(str);
            //    }
            //}
            //catch (Exception ex)
            //{

            //    Console.WriteLine(ex.Message);
            //}
            #endregion
        }