素数判定
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 37390 Accepted Submission(s): 12820
Problem Description
对于表达式n^2+n+41,当n在(x,y)范围内取整数值时(包括x,y)(-39<=x<y<=50),判定该表达式的值是否都为素数。
Input
输入数据有多组,每组占一行,由两个整数x,y组成,当x=0,y=0时,表示输入结束,该行不做处理。
Output
对于每个给定范围内的取值,如果表达式的值都为素数,则输出"OK",否则请输出“Sorry”,每组输出占一行。
Sample Input
0 1
0 0
Sample Output
OK
1 import java.util.Scanner; 2 public class Main{ 3 public static boolean Prime(int n){ 4 boolean flag = true; 5 for(int i=2;i<=Math.sqrt(n);i++) 6 if(n%i==0){ 7 flag = false; 8 break; 9 } 10 return flag; 11 } 12 public static void main(String[] args) { 13 Scanner scan = new Scanner(System.in); 14 int x,y = 0; 15 String str; 16 while(true){ 17 x = scan.nextInt(); 18 y = scan.nextInt(); 19 if(x==0&&y==0) 20 break; 21 else{ 22 str = "OK"; 23 for(int i=x;i<=y;i++){ 24 if(!Prime(i*i+i+41)){ 25 str = "Sorry"; 26 break; 27 } 28 } 29 } 30 System.out.println(str); 31 } 32 } 33 }