练习题 第一单元 1和11

第一题

int n;
            int result = 0;
            Console.Write("请输入一个正整数:");
            n = int.Parse(Console.ReadLine());
            if (n % 2 == 0)
            {
                for (int i = 1; i <= n / 2; i++)
                {
                    result = result + 2 * i;
                }
            }
            else
            {
                for (int i = 1; i <= (n / 2) + 1; i++)
                {
                    result = result + 1 + 2 * (i - 1);
                }
            }
            Console.WriteLine(result);

            //S:
            //Console.WriteLine("按回车键结束");
            //var s = Console.Read();
            //if (s == '\n')

            //    Console.ReadKey();
            //else
            //    goto S;
            var s = 0;
            Console.WriteLine("按回车键结束");
            do
            {
                s = Console.Read();
            } while (s == '\n');

 

 

 

 

 

第十一题

class Program
    {
        static void Main(string[] args)
        {
            int i;
            string s_text, s_key,s_result=null;
           
            Console.WriteLine("请输入原字符串：");
            s_text = Console.ReadLine();
            Console.WriteLine("请输入密钥字符串：");
            s_key = Console.ReadLine();
            char[] ch = new char[s_text.Length];
            if (s_text.Length != s_key.Length)
            {
                Console.WriteLine("密钥字符串与原字符串长度必须相等");
            }
            for (i = 0; i < s_text.Length; i++)
            {
                ch[i] = (char)(s_text[i] ^ s_key[i]);
                s_result += ch[i];
            }
            Console.WriteLine(s_result);
            Console.WriteLine("按回车键结束");
            Console.ReadKey();
        }
    }