java 一系列数组函数，可以确定nubmer是否为素数

Posted 2021-05-08

import java.util.Arrays;

public class isprime {
    public static void main(String[] args) {
        System.out.println(isprime(8));
    }
    public static int[] intarr(int...args) {
        return args;
    }
    public static String[] strarr(String...args) {
        return args;
    }
    public static int[] intrange(int limit) {
        int[] lst = new int[limit];
        for(int i=0; i < limit; i++) {
            lst[i] = i;
        }
        return lst;
    }
    public static int[] int_interval(int start, int end) {
        int[] lst = new int[end-start];
        int assigner = start;
        for(int i=0; i < end-start; i++) {
            lst[i] = assigner;
            assigner++;
        }
        return lst;
    }
    public static int[] oddrange(int limit) {
        int[] lst = new int[limit/2];
        int oddcount = 0;
        for(int i=0; i < limit;i++) {
            if (i%2 != 0) {
                lst[oddcount] = i;
                oddcount ++;
            }
        }
        return lst;
    }
    public static boolean isprime(int num) {
        int[] checklist = int_interval(2, num);
        boolean result = true;
        for(int elem: checklist) {
            if (num % elem == 0) {
                result = false;
            }
        }
        return result;
    }
}