using System;public class Test { static void Main() { int N = 100; Console.Write(2); for (int i = 3; i < N; i += 2) { for (int k = 3; k <= (int)Math.Sqrt(i); k += 2) { if (i % k == 0) goto next; } Console.Write(" {0}", i); next: ; } } }
private string Test(int N) { string strTemp=""; for (int i = 3; i < N; i++) { if(i%2==0) { continue; } for (int j = 3; j< (int)Math.Sqrt(i);j++) { if (i!=j && i % j == 0) { goto next; } } strTemp+=i+"|"; next: ; } return strTemp; }
{
static void Main()
{
int N = 100;
Console.Write(2);
for (int i = 3; i < N; i += 2)
{
for (int k = 3; k <= (int)Math.Sqrt(i); k += 2)
{
if (i % k == 0) goto next;
}
Console.Write(" {0}", i);
next: ;
}
}
}
{
string strTemp=""; for (int i = 3; i < N; i++)
{
if(i%2==0)
{
continue;
}
for (int j = 3; j< (int)Math.Sqrt(i);j++)
{
if (i!=j && i % j == 0)
{
goto next;
}
}
strTemp+=i+"|";
next: ;
}
return strTemp;
}
改为for (int j = 3; j<= (int)Math.Sqrt(i);j++)
for (int j = 3; j< (int)Math.Sqrt(i);j++)
{
if (i!=j && i % j == 0)
{
goto next;
}
为什么能判断是质数?
Math.Sqrt有什么意义?
能不能请各位详细解释一下。谢谢各位!