C# 練習

標籤：namespace   adl   偶數   text   int   cti   else   parse   ace   

1、

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace _17._9._18
{

 class Program
    {
        static void Main(string[] args)
        {
            Console.Write("請輸入一個整數：");
            int n = int.Parse(Console.ReadLine());
            int sum=0;
            if(n%2!=0)
            {
                for(int i=1;i<=n;i++)
                {
                    if (i % 2 != 0)
                        sum += i;
                }
                Console.Write("該數及比該數小的所有奇數之和為：");
                Console.WriteLine(sum);
                Console.Read();
            }
            else
            {
                for (int j = 2; j <= n; j++)
                {
                    if (j % 2 == 0)
                        sum += j;
                }
                Console.Write("該數及比該數小的所有偶數之和為；");
                Console.WriteLine(sum);
                Console.Read();
               
            }
        }
    }
}

C# 練習