HDOJ 1395 2^x mod n = 1

HDACM 1395

需注意 n为偶数或者1时minimum 是不存在的。

import java.util.Scanner;public class Main{    public static void main(String[] args) {        Scanner sc = new Scanner(System.in);        while (sc.hasNext()) {            int n = sc.nextInt();            if (n%2==0||n==1) {                System.out.println("2^? mod "+n+" = 1");                continue;            }            int num = 2;            int x = 1;            while (num%n!=1) {                num = num << 1;                num = num%n;                x++;            }            System.out.println("2^"+x+" mod "+n+" = 1");        }        sc.close();    }}