用筛选法求素数
package itheima2;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt();
int Prime[] = new int[n+1];
for (int i = 0; i < n + 1; i++) {
Prime[i] = i;
}
Prime[1] = 0;
int m = (int)Math.sqrt(n);
for(int i=2;i<=m;i++){
if(Prime[i] != 0){
for(int j=2*i;j<=n;j+=i){
Prime[j] = 0;
}
}
for (int k = 2; k < n + 1; k++) {
System.out.print(Prime[k] + " ");
}
System.out.println();
}
}
}