算法 第二周作业

2.1

import java.util.Scanner;public class suanfa {public static void main(String args[]) {long k1;Scanner scan = new Scanner(System.in);System.out.println("Enter one number:");k1 = scan.nextInt();isPrime(k1);}public static int isPrime(long a) {boolean e = true;for (long i = a - 1; i > 1; i--) {if (a % i == 0) {e = false;}}if (e) {System.out.println(1);} elseSystem.out.println(0);return 0;}}

2.2

import java.util.Random;import java.util.Scanner;public class suanfa {public static void main(String args[]) {int k1;Scanner scan = new Scanner(System.in);System.out.println("Enter one number:");k1 = scan.nextInt();System.out.println(createRndInteger(k1));// 生成随机字节}public static long createRndInteger(int n) {int a = 0;// 判断输入的值if (n <= 0)return 0;StringBuffer result = new StringBuffer("1");for (int i = 0; i < n - 1; i++) {boolean b = new Random().nextBoolean();if (b) {a = 1;} elsea = 0;result.append(a);}return Long.parseLong(result.toString());}}