循环

//语句的分类：顺序，分支，循环
            //循环语句
            //for (int i=1;i<=10 ;i++ )
            //{
            //    Console.WriteLine("你好");
            //}
            //Console.ReadLine();

            //死循环
            //for (; ; )
            //{
            //    Console.WriteLine("Hello");
            //}

            //输入一个整数，计算从1加到这个数的结果
            //Console.Write("请输入一个正整数：");
            //int a = int.Parse(Console.ReadLine());
            //int sum = 0;
            //for (int i = 1; i <= a; i++)
            //{
            //    sum += i;//sum=sum+i;
            //}

            //Console.WriteLine(sum);
            //Console.ReadLine();

            //输入一个正整数，求阶乘
            //Console.Write("请输入一个正整数：");
            //int a = int.Parse(Console.ReadLine());
            //int sum = 1;
            //for (int i = 1; i <= a; i++)
            //{
            //    sum *= i;//sum=sum*i;
            //}

            //Console.WriteLine(sum);
            //Console.ReadLine();

            //输入一个正整数，求阶乘的和1!+2!+...+n!
            //Console.Write("请输入一个正整数：");
            //int a = int.Parse(Console.ReadLine());
            //int sum = 1;
            //int sum1 = 0;
            //for (int i = 1; i <= a; i++)
            //{
            //    sum *= i;//sum=sum*i;
            //    if (i == 4)//不想要4的
            //    {
            //        continue;//终止本次循环，继续下次循环
            //    }
            //    sum1 += sum;
            //}

            //Console.WriteLine(sum1);
            //Console.ReadLine();

            //一个游戏，前20关是每一关自身的分数，
            //21-30关每一关是10分
            //31-40关，每一关是20分
            //41-49关，每一关是30分
            //50关，是100分
            //输入你现在闯到的关卡数，求你现在拥有的分数
           // 两种做法：if嵌套for    for嵌套if
            Console.Write("请输入您现在闯到的关卡数：");
            int guan = int.Parse(Console.ReadLine());
            if (guan >= 1 && guan <= 50)
            {
                int sum = 0;
                if (guan <= 20)
                {
                    for (int i = 1; i <= guan; i++)
                    {
                        sum += i;
                    }
                }
                else if (guan <= 30)
                {
                    for (int i = 1; i <= 20; i++)
                    {
                        sum += i;
                    }
                    for (int i = 21; i <= guan; i++)
                    {
                        sum += 10;
                    }
                }
                else if (guan <= 40)
                {
                    for (int i = 1; i <= 20; i++)
                    {
                        sum += i;
                    }
                    for (int i = 21; i <= 30; i++)
                    {
                        sum += 10;
                    }
                    for (int i = 31; i <= guan; i++)
                    {
                        sum += 20;
                    }
                }
                else if (guan <= 49)
                {
                    for (int i = 1; i <= 20; i++)
                    {
                        sum += i;
                    }
                    for (int i = 21; i <= 30; i++)
                    {
                        sum += 10;
                    }
                    for (int i = 31; i <= 40; i++)
                    {
                        sum += 20;
                    }
                    for (int i = 41; i <= guan; i++)
                    {
                        sum += 30;
                    }
                }
                else//50关
                {
                    for (int i = 1; i <= 20; i++)
                    {
                        sum += i;
                    }
                    for (int i = 21; i <= 30; i++)
                    {
                        sum += 10;
                    }
                    for (int i = 31; i <= 40; i++)
                    {
                        sum += 20;
                    }
                    for (int i = 41; i <= 49; i++)
                    {
                        sum += 30;
                    }
                   // sum += 100;
                    for (int i = 50; i == 50; i++)
                    { sum += 100; }
                }
                Console.WriteLine(sum);
            }
            else
            {
                Console.WriteLine("输入有误！");
            }
            Console.ReadLine();

            //Console.Write("请输入您现在闯到的关卡数：");
            //int guan = int.Parse(Console.ReadLine());
            //if (guan <= 50 && guan >= 1)
            //{
            //    int sum = 0;
            //    for (int i = 1; i <= guan; i++)
            //    {
            //        if (i <= 20)
            //        {
            //            sum += i;
            //        }
            //        else if (i <= 30)
            //        {
            //            sum += 10;
            //        }
            //        else if (i <= 40)
            //        {
            //            sum += 20;
            //        }
            //        else if (i <= 49)
            //        {
            //            sum += 30;
            //        }
            //        else
            //        {
            //            sum += 100;
            //        }
            //    }
            //    Console.WriteLine(sum);
            //}
            //else
            //{
            //    Console.WriteLine("输入有误！");
            //}
            //Console.ReadLine();

            //找出100以内与7有关的数并打印、
            //（1）.从1找到100
            //（2）.找出与7有关的数
            //    个位数是7 a%10==7
            //    十位数是7 a/10 ==7
            //    能被7整除 a%7 ==0
            //for (int i = 1; i <= 100; i++)
            //{
            //    if (i % 7 == 0 || i % 10 == 7 || i / 10 == 7)
            //    {
            //        Console.Write(i+" ");
            //    }
            //}
            //Console.ReadLine();

        }