完全数

如果一个正整数等于除它本身之外其他所有除数之和，就称之为完全数。
完全数

for(int i = 1; i < 1000; i++)
{
int sum = 0;
for(int j = 1; j < i; j++)
{
if (i % j == 0)
{
sum += j;
}
}
if (sum == i)
{
Console.WriteLine(i);
}

代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp3
{
    class Program
    {
        static void Main(string[] args)
        {
            for(int i = 1; i < 1000; i++)
            {
                int sum = 0;
                for(int j = 1; j < i; j++)
                {
                    if (i % j == 0)
                    {
                        sum += j;
                    }
                 }
                if (sum == i)
                {
                    Console.WriteLine(i);
                }
               
            }
            Console.ReadKey();
        }
    }
}

结果

以前以内的完全数 6 28 496

输出所有水仙花数

水仙花数是三位数的数，其各位数字的立方和等于该数的本身
水仙花

int a, b, c;
for(int i = 100; i < 1000; i++)
{
a = i / 100;
b = i / 10 %10;
c = i % 10;
if (a * a * a + b * b * b + c * c * c == i)
{
Console.WriteLine(i);
}

代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp4
{
    class Program
    {
        static void Main(string[] args)
        {
            int a, b, c;
            for(int i = 100; i < 1000; i++)
            {
                a = i / 100;
                b = i / 10 %10;
                c = i % 10;
                if (a * a * a + b * b * b + c * c * c == i)
                {
                    Console.WriteLine(i);
                }
            }
            Console.ReadKey();
        }
    }
}

结果

水仙花数为 153 370 371 407

类的使用

代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp6
{
    class Student
    {
        public string name;
        public string sex;
        public int age;
        public Student(string name, string sex)
        {

        }
        public Student(string name, string sex,int age)
        {
            this.name = name;
            this.sex = sex;
            this.age = age;

        }
        public void Inderduce()
        {
            Console.WriteLine("我叫"+this.name+"我是一个"+this.sex+"孩，我今年"+this.age+"岁");

        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Student s1 = new Student("小华","男",20);
            Student s2 = new Student("小花","女",18);
            s1.Inderduce();
            s2.Inderduce();
            Console.ReadKey();

        }
    }
}