1、判断一个数是否是水仙花数Console.WriteLine("请输入一个数字");int num = int.Parse(Console.ReadLine());int a = num % 10;//个位int b = num % 100 / 10;//十位 int c = num / 100;//百位int sum = a * a * a + b * b * b + c * c * c;if (sum == num){ Console.WriteLine("{0}是水仙花数",num);}else{ Console.WriteLine("{0}不是水仙花数", num);}2、判断一个年份的某个月又多少天 Console.WriteLine("请输入一个年份"); int year = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("请输入一个年份"); int mother = Convert.ToInt32(Console.ReadLine());switch (mother) {case 1:case 3:case 5:case 7:case 8:case 10:case 12:Console.WriteLine("31天");break;case 2:if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0){Console.WriteLine("29天"); break;}else{Console.WriteLine("28天"); break;}case 4:case 6:case 9:case 11:Console.WriteLine("30天");break;default:Console.WriteLine("错误的月份");break;}