随笔，关于生成随机数，排序

生成N个随机数，N<100W,不能重复

Console.WriteLine(DateTime.Now.ToLongTimeString());
Random random = new Random();
Byte[] bytes = new Byte[1000000];
StreamWriter sw = new StreamWriter("Values.txt", true);
for (int i = 0; i < 1000000; i++){
    var result = random.Next(0, 1000000);
    if(bytes[result] == 1) 
    {
        continue;
    }
    bytes[i] = 1;
    sw.WriteLine(result);
    sw.Flush();
}
sw.Close();
Console.WriteLine(DateTime.Now.ToLongTimeString());
Console.Read();

接上题，对N个随机数进行排序，N<100W

StreamReader sr = new StreamReader("Values.txt");
Byte[] bytes = new Byte[1000000];
Console.WriteLine(DateTime.Now.ToLongTimeString());
while (!sr.EndOfStream)
{
    bytes[Int32.Parse(sr.ReadLine())] = 1;
}
sr.Close();

StreamWriter sw = new StreamWriter("Values2.txt", true);
for (int i = 0; i < 1000000; i++)
{
    if(bytes[i] == 1) 
    {
        sw.WriteLine(i);
        sw.Flush();
    }
}
sw.Close();
Console.WriteLine(DateTime.Now.ToLongTimeString());
Console.Read();

整个排序过程耗时2秒，大约70W条记录