不能创造巨大的数组 [英] Can't create huge arrays
问题描述
像许多其他的程序员，我走进素数，并作为他们来说，我喜欢的是挑战，所以我不是在寻找像的注释阿特金这样做比你老兄的速度更快，但只是一个解决办法 - 或者至少是一个暗示 - 我的问题。
Like many other programmers, I went into primes, and as many of them, what I like is the challenge, so I'm not looking for comment like Atkin did this faster than you dude, but just a solution - or at least an hint - to my issue.
我需要创建大阵列（如大小> int.MaxValue ）。于是，我去了很多的网页，发现 gcAllowVeryLargeObjects元素之一。我以为我得救了，添加以下魔法我的的App.config ：
I need to create big arrays (like size > int.MaxValue). So I went to a lot of web pages and found the gcAllowVeryLargeObjects Element one. I thought I was saved, add the following magic to my App.config:
<configuration>
<runtime>
<gcAllowVeryLargeObjects enabled="true" />
</runtime>
</configuration>
但它的没有的工作。这里的code我使用：
But it didn't worked. Here's the code I use :
void go(object sender, EventArgs eventArgs)
{
t.Stop();
ulong maxprime = 10;
Stopwatch stopwatch = new Stopwatch();
string s = String.Empty;
while (maxprime < ulong.MaxValue)
{
stopwatch.Restart();
richTextBox2.Text += Environment.NewLine + ("Max \t= " + maxprime.ToString("N0"));
try
{
richTextBox2.Text += Environment.NewLine + ("Count \t= " + GetAllPrimesLessThan(maxprime).Count);
richTextBox2.Text += Environment.NewLine + ("Time \t= " + stopwatch.Elapsed);
richTextBox2.Text += Environment.NewLine + ("--------------------------------");
maxprime *= 10;
richTextBox2.Refresh();
}
catch (Exception exception)
{
s = exception.Message + "; Allocation size: " + (maxprime + 1).ToString("N0");
break;
}
}
if (!string.IsNullOrEmpty(s))
{
richTextBox2.Text += Environment.NewLine + s;
}
richTextBox2.Text += Environment.NewLine + ("Done.");
}
private static List<ulong> GetAllPrimesLessThan(ulong maxPrime)
{
var primes = new List<ulong>() { 2 };
var maxSquareRoot = Math.Sqrt(maxPrime);
var eliminated = new bool[maxPrime + 1];
for (ulong i = 3; i <= maxPrime; i += 2)
{
if (!eliminated[i])
{
primes.Add(i);
if (i < maxSquareRoot)
{
for (ulong j = i * i; j <= maxPrime; j += 2 * i)
{
eliminated[j] = true;
}
}
}
}
return primes;
}
这此输出：
[...]
Max = 1 000 000 000
Count = 50847534
Time = 00:00:15.3355367
--------------------------------
Max = 10 000 000 000
Array dimensions exceeded supported range.; Allocation size: 10 000 000 001
Done.
我
如何才能摆脱这种错误的？
How can I get rid of this error?
FYI：我有
- 16GB内存;
- 32GB内存映射（/分页？）在SSD上;
- 启用64位
推荐答案
从你的链接：
在使用你的应用程序配置文件中该元素可使数组，其超过2 GB大小，但不会改变物体的大小或数组大小其他限制：
Using this element in your application configuration file enables arrays that are larger than 2 GB in size, but does not change other limits on object size or array size:
在任何单一维度的最高指数为2147483591（0x7FFFFFC7）用于其他类型的字节数组和单字节结构数组和2146435071（0X7FEFFFFF）。
The maximum index in any single dimension is 2,147,483,591 (0x7FFFFFC7) for byte arrays and arrays of single-byte structures, and 2,146,435,071 (0X7FEFFFFF) for other types.
又见<一个href=\"http://stackoverflow.com/questions/2338778/what-is-the-maximum-length-of-an-array-in-net-on-64-bit-windows\">What在64位Windows 在.NET中的数组的最大长度：
See also What is the maximum length of an array in .NET on 64-bit Windows:
这是数组，理论上最多有2,147,483,647元，，因为它使用索引的int 。
An array could theoretically have at most 2,147,483,647 elements, since it uses an int for indexing.
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