import java.util.*;public class YesOrNo { public static void main(String args[]){ Scanner s = new Scanner(System.in);
int i = s.nextInt();
do { int k = (int)Math.sqrt(i)+1;
for(int j = 2; j<= k; j++){ if (i%j == 0){ System.out.println(i +" 不是素数"); break; } if (j >= k) System.out.println(i +" 是素数"); } i = s.nextInt(); }while (i != -1);
System.out.println("Exit"); } }
主类public class Test { public static void main(String[] args) { String str; InputStreamReader stdin = new InputStreamReader(System.in);// 键盘输入 BufferedReader bufin = new BufferedReader(stdin); try { System.out.print("请输入一个整数: "); str = bufin.readLine(); int num = Integer.parseInt(str); if(NumberUtils.isPrimeNum(num)) System.out.println(num+"是一个素数"); else System.out.println(num+"不是一个素数"); } catch (IOException e) { System.out.println("发生I/O错误!!!"); }catch (NumberFormatException e) { System.out.println("您输入的数据格式不正确,请输入一个整数!"); } }} 工具类public class NumberUtils { public static boolean isPrimeNum(int num) { if (num <= 2) { return num == 2; } if (num % 2 == 0) { return false; } int iSqrt = (int) Math.sqrt(num); for (int i = 3; i <= iSqrt; i += 2) { if (num % i == 0) { return false; } } return true; } }
//判断素数类package com.test.ques;public class IsPrimNumber {
public static boolean isPriNum(int n) {
for (int i = 2; i <=Math.sqrt(n); i++) { if (n % i == 0) return false; } return true; }
} //卖main 方法类package com.test.ques;import java.util.Scanner;public class Input { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int i = sc.nextInt(); boolean a = IsPrimNumber.isPriNum(i);
if(a)System.out.println("is prim number"); else System.out.println("is not a prim number");
public static void main(String args[]){
Scanner s = new Scanner(System.in);
int i = s.nextInt();
do {
int k = (int)Math.sqrt(i)+1;
for(int j = 2; j<= k; j++){
if (i%j == 0){
System.out.println(i +" 不是素数");
break;
}
if (j >= k)
System.out.println(i +" 是素数");
}
i = s.nextInt();
}while (i != -1);
System.out.println("Exit");
}
}
String str;
InputStreamReader stdin = new InputStreamReader(System.in);// 键盘输入
BufferedReader bufin = new BufferedReader(stdin);
try {
System.out.print("请输入一个整数: ");
str = bufin.readLine();
int num = Integer.parseInt(str);
if(NumberUtils.isPrimeNum(num))
System.out.println(num+"是一个素数");
else
System.out.println(num+"不是一个素数");
} catch (IOException e) {
System.out.println("发生I/O错误!!!");
}catch (NumberFormatException e) {
System.out.println("您输入的数据格式不正确,请输入一个整数!");
}
}}
工具类public class NumberUtils {
public static boolean isPrimeNum(int num) {
if (num <= 2) {
return num == 2;
}
if (num % 2 == 0) {
return false;
} int iSqrt = (int) Math.sqrt(num); for (int i = 3; i <= iSqrt; i += 2) {
if (num % i == 0) {
return false;
}
}
return true;
}
}
{
public static boolean isPriNum(int n)
{
for (int i = 2; i <=Math.sqrt(n); i++)
{
if (n % i == 0)
return false;
}
return true;
}
}
//卖main 方法类package com.test.ques;import java.util.Scanner;public class Input {
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
int i = sc.nextInt();
boolean a = IsPrimNumber.isPriNum(i);
if(a)System.out.println("is prim number");
else System.out.println("is not a prim number");
}}