注意:
1不是素数
2求素数可以考虑开平方的方法
方法一:
public class prime {
public static void main(String[] args) {
int len = 100;
int count = 0;
int j;
System.out.print(len+"以内的素数为:");
for (int i = 2; i < len; i++) {
int k = (int) Math.sqrt(i);
for (j = 2; j <= k; j++) {
if (i%j == 0) {
break;
}
}
if (j>k) {
count++;
System.out.print(i+" ");
}
}
System.out.println();
System.out.println("素数的个数:"+count);
}
}
方法二:
public class prime {
public static void main(String[] args) {
int len = 100;
int count = 1;
System.out.print(len+"以内的素数为:"+2+" ");
for (int i = 3; i < len; i++) {
boolean is = true;
int k = (int) Math.sqrt(i);
for (int j = 2; j <= k; j++) {
if (i%j == 0) {
is = false;
break;
}
}
if (is == true) {
count++;
System.out.print(i+" ");
}
}
System.out.println();
System.out.println("素数的个数:"+count);
}
}