判断素数
public class Au { public static void main(String[] args) { // TODO Auto-generated method stub Scanner in = new Scanner(System.in); int n = in.nextInt(); int isprime = 1; for(int i=2; i<n; i++){ if(n%i == 0){ isprime = 0; break; } } if(isprime == 1){ System.out.print(n+"是素数"); } else{ System.out.println(n+"不是素数"); } } }
以此基础上对代码进行调整,输出100以内的素数:
public class Au { public static void main(String[] args) { // TODO Auto-generated method stub // Scanner in = new Scanner(System.in); // int n = in.nextInt(); for(int n=2; n<100; n++){ int isprime = 1; for(int i=2; i<n; i++){ if(n%i == 0){ isprime = 0; break; } } if(isprime == 1){ System.out.print(n+" "); } else{ // System.out.println(n+"不是素数"); } } } }
输出结果:
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
更进一步,输出前50个素数:
public class Au { public static void main(String[] args) { // TODO Auto-generated method stub // Scanner in = new Scanner(System.in); // int n = in.nextInt(); int count = 0; for(int n=2; count<=50; n++){ int isprime = 1; for(int i=2; i<n; i++){ if(n%i == 0){ isprime = 0; break; } } if(isprime == 1){ System.out.print(n+" "); count++; } else{ // System.out.println(n+"不是素数"); } } } }
时间: 2024-08-03 14:33:16