[C#] 判斷星期幾

星期一 ~ 星期日

var today = DateTime.Now;


if (today.DayOfWeek == DayOfWeek.Monday)

if (today.DayOfWeek == DayOfWeek.Tuesday)

if (today.DayOfWeek == DayOfWeek.Wednesday)

if (today.DayOfWeek == DayOfWeek.Thursday)

if (today.DayOfWeek == DayOfWeek.Friday)

if (today.DayOfWeek == DayOfWeek.Saturday)

if (today.DayOfWeek == DayOfWeek.Sunday)

...

[Logic] Find the unique number

題目 :
There is an array with some numbers. All numbers are equal except for one. Try to find it!

findUniq([ 1, 1, 1, 2, 1, 1 ]) === 2
findUniq([ 0, 0, 0.55, 0, 0 ]) === 0.55

-----

my ans :
 public static int GetUnique(IEnumerable<int> numbers)
  {
     var result = numbers.GroupBy(
      c => c,
      (key,g) => new { a = key, count = g.Count()})
      .Where(c => c.count == 1)
      .Select(c => c.a).Single();

     return result;
  }

[Logic] IQ Test

題目 :

Bob is preparing to pass IQ test. The most frequent task in this test is to find out which one of the given numbers differs from the others. Bob observed that one number usually differs from the others in evenness. Help Bob — to check his answers, he needs a program that among the given numbers finds one that is different in evenness, and return a position of this number.

! Keep in mind that your task is to help Bob solve a real IQ test, which means indexes of the elements start from 1 (not 0)

##Examples :

IQ.Test("2 4 7 8 10") => 3 // Third number is odd, while the rest of the numbers are even

IQ.Test("1 2 1 1") => 2 // Second number is even, while the rest of the numbers are odd


不加思索的弱code :

var list = numbers.Split(' ');
var temp = int.Parse(list[0]) % 2;
var temp2 = int.Parse(list[1]) % 2;
var count = 3;

for (int i = 2; i < list.Count(); i++)
{
var a = int.Parse(list[i])% 2;
if ( a != temp && temp == temp2 )
{
break;
}
else if ( a != temp && temp != temp2 )
{
count = 1;
break;
}
else if ( a != temp2 && temp != temp2 )
{
count = 2;
break;
}
count++;
}
return count++;

---

優雅的code :

  var nums = numbers.Split(' ').Select(n => int.Parse(n));
  var isEven = nums.Count(n => n % 2 == 0) == 1;
  return nums.Select(n => n % 2 == (isEven ? 0 : 1)).ToList().IndexOf(true) + 1;

[SQL] sql server 定期資料庫備份

定期因為容量不足,因此把原本的完整備份調整為差異備份,

因此簡單介紹一下設定備份流程

[C#] winfrom 關閉後,後台程序依舊執行中問題

之前一直遇到這樣的問題，導致同仁無法正常更新

查了一下，似乎是舊程式沒有在form表單關閉時在觸發解構相關事件

所以補上了下述，看看之後情況會部會改善

 private void frmMain_FormClosed(object sender, FormClosedEventArgs e)
        {
            //FormClosed事件程式碼
            Dispose();
            Application.Exit();     
        }

[C#] 西元年轉民國年格式

需求是將西元年日期轉為民國格式日期,以下做個method 紀錄

ex.2017/01/31 --> 106/01/31

 public class DateHelper
    {
        /// <summary>
        /// 解析成民國時間 ex.106/01/31
        /// </summary>
        /// <param name="datetime">西元時間</param>
        /// <returns></returns>
        public static string ParseToTaiwanDate(DateTime datetime)
        {
            System.Globalization.TaiwanCalendar tc = new System.Globalization.TaiwanCalendar();

            return string.Format("{0}/{1}/{2}",
                tc.GetYear(datetime),
                datetime.Month.ToString("00"),
                datetime.Day.ToString("00"));
        }

        public static string ParseToTaiwanYearMonth(DateTime datetime)
        {
            System.Globalization.TaiwanCalendar tc = new System.Globalization.TaiwanCalendar();

            return string.Format("{0}/{1}",
                tc.GetYear(datetime),
                datetime.Month.ToString("00"));
        }

        public static string ParseToTaiwanYear(DateTime datetime)
        {
            System.Globalization.TaiwanCalendar tc = new System.Globalization.TaiwanCalendar();

            return string.Format("{0}",
                tc.GetYear(datetime));
        }
    }

[C#] 取得前一月的月初、月末日

ref :  並自行修改

DateTime FirstDay = DateTime.Now.AddMonths(-1).AddDays(-DateTime.Now.AddMonths(-1).Day+1);
 DateTime LastDay = DateTime.Now.AddDays(-DateTime.Now.Day);