123456789四則運算

代碼說明：在123456789或987654321中插入+-*/四則符號來算出一個固定的值。asc爲true時是123456789，反之爲987654321。

123456789算100，C#下時間爲15秒，VBA下爲56秒，快了3/4。

版權說明：本文來自狼版http://blog.csdn.net/northwolves/archive/2009/11/20/4841068.aspx一文，試着用C#實現了一下。初學C#，如果哪邊有什麼不對或可以優化，請大家指點。

 

static void GetAllResult(int result, Boolean asc) { int temp=0,num=0; string[] x = new string[9]; string[] op = new string[5]{"+","-","*","/",""}; string outResult; StringBuilder sb = new StringBuilder(); Stopwatch sw = new Stopwatch(); sw.Start(); Console.WriteLine("運算中，請稍候......"); for (int i = 0; i <= Math.Pow(5,8); i++) { temp = i; x[0] = (asc ? 1 : 9).ToString(); for (int j = 1; j <= 8; j++) { x[j] = op[temp % 5] + (asc?j + 1: 9 - j).ToString(); temp=temp /5; } outResult = string.Join("",x); if ((new DataTable().Compute(outResult ,null)).ToString() == result.ToString()) { num++; sb.Append("解 " + num + ":/t" + outResult + "=" + result + "/n"); } } Console.WriteLine(sb.ToString()); sw.Stop(); Console.WriteLine(sw.Elapsed.ToString()); Console.ReadLine(); } static void Main(string[] args) { GetAllResult(100,true); }