Definition: Prime numbers are also called prime numbers. A natural number greater than 1, except 1 and itself, a number that cannot be divisible by other natural numbers is called a prime number; otherwise it is called a composite number (it is specified that 1 is neither a prime number nor a composite number)
code:
package 练习;
import java.util.Scanner;
public class Text {
public static int fn(int n) {
int j,k;
k=(int)Math.sqrt(n);
for(j=2;j<=k;j++) {
if(n%j==0) {
return 0;
}
}
return 1;
}
public static void main(String[] args) {
int i,m=0,t;
Scanner ming =new Scanner(System.in);
t=ming.nextInt();
for(i=2;i<=t;i++)
{
if(fn(i)==1) {
System.out.print(i+" ");
m++;
if(m%10==0){
System.out.println();
m=0;
}
}
}
}
}
10
2 3 5 7