C#模数运算符(％)无法正常工作? [英] C# modulus operator (%) not working?

问题描述

问候:)

我正在尝试编写代码来计算200,000到400,000之间的素数之和.

但是当我运行它时，结果是0！调试它，似乎问题出在％"运算符！谁能告诉我怎么了? (下面的功能-我对代码进行了过多拆分以帮助调试，对此感到抱歉).

Greetings :)

I''m trying to write a code to calculate the sum of prime numbers between 200,000 and 400,000.

but when I run it, it gives me 0 as a result! debugged it and seems the problem is with the "%" operator! can anyone tell me what''s wrong please? (functions below - I split the code too much to help debug, sorry about that).

private string SolveProblem2()
{
	double loopEnd = 200000, numCurrent = 200000;
	BigInteger sum = new BigInteger("0");

	for (int i = 0; i < loopEnd ; i++, numCurrent++)
	{
		SolveProblem2_1(numCurrent, ref sum);
	}

	return sum.ToString(); //returns final result

}


private void SolveProblem2_1(double numCurrent, ref BigInteger sum)
{
	int j = 2;
	double res = 0;

	while (j < numCurrent)
	{
		res = numCurrent % j;
		if (res == 1)
		{
			j++;
		}
		else
		{
			break;
		}
	}

	if (j == numCurrent)
	{
		sum = sum.add(new BigInteger(numCurrent.ToString()));
	}

}

请注意，由于它是素数(由朋友的另一个代码提供)，因此我使用了200003进行测试，但是根据我的代码，它可以被3除以除一个以外的余数！

Note that I used 200,003 for testing since its a Prime number (given by a friend''s another code), but according to my code it can be divided by 3 with a remainder other than one!

推荐答案

应该是

Shouldnt this be

if (numCurrent % j== 0)

?

如果您选择10％3，则提醒将为1..请参见此处的示例(我知道它的VB，但示例仍然有效:)):
http://msdn.microsoft.com/en-us/library/se0w9esz％28v = vs.110％29.aspx [ ^ ]

instead?

If you take 10 % 3 the reminder would be 1.. See examples here (I know its VB but examples still valid :) ):
http://msdn.microsoft.com/en-us/library/se0w9esz%28v=vs.110%29.aspx[^]

这篇关于C#模数运算符(％)无法正常工作?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！