JAVA----練習(3.10)

獲取一個數二進制序列中所有的偶數位和奇數位， 分別輸出二進制序列

import java.util.Scanner;
public class TestDemo {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();//-1

        for (int i = 31; i >= 1; i -= 2) {
            System.out.print (  ((n >>> i) & 1) + " "  );
        }
        System.out.println();
        for (int i = 30; i >= 0; i -= 2) {
            System.out.print (  ((n >>> i) & 1) + " "  );
        }
    }
}

編寫代碼模擬三次密碼輸入的場景。 最多能輸入三次密碼，密碼正確，提示“登錄成功”,密碼錯誤， 可以重新輸 入，最多輸入三次。三次均錯，則提示退出程序

import java.util.Scanner;
public class InputPassword {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int count = 3;
        System.out.println("請輸入正確的密碼，您有3次機會！");
        while(count != 0) {
            System.out.println("請輸入正確的密碼：");
            String password = scan.next();
            if(password.equals("6928360")) {
                System.out.println("登錄成功！");
                break;
            } else {
                count--;if(count==0) {
                    System.out.println("你已經輸錯3次密碼,程序退出 ");
                } else {
                    System.out.println("登錄失敗，你還有 " + count +"次機會！ ");
                }
            }
        }
    }
}

輸出n*n的乘法口訣表，n由用戶輸入。

import java.util.Scanner;
public class TestDemo {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        System.out.println(n+"*"+n+"乘法表");
        System.out.println();
        for (int i = 1;i <= n ; i++) {
            for (int j = 1;j <= i ;j++ ) {
                System.out.print (i+"*"+j+"="+i*j +" ");
            }
            System.out.println();
        }
    }
}

遞歸輸出一個整數n的每一位

import java.util.Scanner;
public class TestDemo {
    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        OneBit(n);
    }
    //輸出每一位
    public static void OneBit(int n){
        if(n > 9){
            OneBit(n / 10);
        }
        //n <= 9時,n % 10輸出這一位
        System.out.print(n % 10 + " ");
    }
}