学步园

//以单词为单位对字符串进行翻转，先按照字母进行翻转，然后按照单词进行翻转

            string str1 = "12345     67890";
            string str2 = "";
            string str3 = "";

            for (int o = str1.Length - 1; o >= 0; o--)
                str2 += str1[o];//按字母翻转
            char[] chArr = new char[str1.Length];

            int i = 0;
            int j = 0;
            int index = 0;
            while (index < str2.Length-1)
            {
                if (str2[index] == ' ')
                {
                    j = index - 1;
                    while (i <= j)
                    {
                        chArr[i] = str2[j];
                        chArr[j] = str2[i];
                        i++;
                        j--;
                    }
                    index++;
                    i = index;
                }
                else
                {
                    index++;
                }
            }
            if (index == str2.Length - 1)
            {
                j = index;
                while (i <= j)
                {
                    chArr[i] = str2[j];
                    chArr[j] = str2[i];
                    i++;
                    j--;
                }
            }

            for (int k = 0; k < str2.Length; k++)
                str3 += chArr[k].ToString();//按照单词翻转

            Console.WriteLine("The reverse letter by letter of   {0}   is   {1}", str1, str2);
            Console.WriteLine("The reverse word by word of   {0}   is   {1}", str1, str3);

            Console.ReadLine();