import java.util.Scanner; public class Main { public static void main(String[] args) { Main main = new Main(); Scanner scan = new Scanner(System.in); int number = scan.nextInt(); System.out.println(main.isPrimeNumber(number)); } public Boolean isPrimeNumber(int number) { if (number==2){ return(true); }if (number==3){ return(true); }else if(number % 2 == 0) { return (false); } else if (number % 3 == 0) { return (false); } else if (number % 5 == 0) { return (false); } else if (number % 7 == 0) { return (false); } else if (number % 9 == 0) { return (false); } else { return (true); } } }hhhh无聊来个有意思的
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc=new Scanner(System.in); int num = sc.nextInt(); System.out.println(isPrime(num)); } public static boolean isPrime(int num){ for (int i = 2; i < Math.sqrt(num); i++) { if (num%i==0){ return false; } } return true; } }
import java.util.Scanner; public class Main { public static void main(String[] args) { Main main = new Main(); Scanner scan = new Scanner(System.in); int number = scan.nextInt(); System.out.println(main.isPrimeNumber(number)); } public Boolean isPrimeNumber(int number) { //write your code here...... if (number < 2) { return false; } int bound = (int)Math.sqrt(number); //判断边界 for (int i = 2; i <= bound; i++) { if (number % i == 0) { return false; } } return true; } }
import java.util.Scanner; public class Main { public static void main(String[] args) { Main main = new Main(); Scanner scan = new Scanner(System.in); int number = scan.nextInt(); System.out.println(main.isPrimeNumber(number)); } public Boolean isPrimeNumber(int number) { //write your code here...... // i只需要循环到根号number即可 for(int i = 2; i*i <= number; i++){ if(number % i == 0){ return false; } } return true; } }
比较简单
import java.util.Scanner; public class Main { public static void main(String[] args) { Main main = new Main(); Scanner scan = new Scanner(System.in); int number = scan.nextInt(); System.out.println(main.isPrimeNumber(number)); } public Boolean isPrimeNumber(int number) { //write your code here...... if (number <= 1) { return false; } for(int i = 2; i < (int)Math.sqrt(number) + 1; i++) { if (number % i == 0) { return false; } } return true; } }
import java.util.Scanner; public class Main { public static void main(String[] args) { Main main = new Main(); Scanner scan = new Scanner(System.in); int number = scan.nextInt(); System.out.println(main.isPrimeNumber(number)); } public Boolean isPrimeNumber(int number) { //write your code here...... //判断i-number之间的数 for(int i = 2;i < number;i++){ //如果进入if则一定不是质数 if(number % i == 0){ return false; } } return true; } }
public class Main { public static void main(String[] args) { Main main = new Main(); Scanner scan = new Scanner(System.in); int number = scan.nextInt(); System.out.println(main.isPrimeNumber(number)); } public Boolean isPrimeNumber(int number) { //write your code here...... for(int i=2;i<(int)Math.sqrt(number);i++) { if(number%i==0) { return false; } } return true; } }
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); int a = in.nextInt(); String flag = "true"; if(a==2||a==3) System.out.println(flag); else{ for(int i=2;i<=a/2;i++){ if(a%i==0){ flag = "false"; break; } } System.out.println(flag); } } }
//write your code here...... // 输入的数字是number且是整数,输出的是true或者false // 所谓的质只能整除1和本事 for (int i=2;i<number;i++){ if(number%i !=0){ continue; //如果余数不是零,那么是质数,接着下一个 }else{ return false; // 如果是零,那么就不是质数,结束循环 } }return true; // 所有数字从小到大都执行完还是没有余数为零的,那么就是质数
public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); int num = in.nextInt(); //判断质数 //就是该数除了1和它本身以外,不再有其他的因数。 for(int i = 2; i < num / 2; i++) { if(num % i == 0) { System.out.println(false); return; } } System.out.println(true); } }
import java.util.Scanner; public class Main { public static void main(String[] args) { Main main = new Main(); Scanner scan = new Scanner(System.in); int number = scan.nextInt(); System.out.println(main.isPrimeNumber(number)); } public Boolean isPrimeNumber(int num) { int x=0; for(int i=2;i<=num;i++){ if(num%i==0){ x=i; break; } } return x!=num?false:true; } }