Java第四周练习+作业

一.练习:

1.输入一个年份,判断是不是闰年(能被4整除但不能被100整除,或者能被400整除)

package com.ym.pc;

import java.util.Scanner;

public class Practice1 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入一个年份");
        int year = input.nextInt();
        if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
            System.out.println("该年份是闰年");
        } else {
            System.out.println("该年份是平年");
        }

    }

}

 

2.输入一个4位会员卡号,如果百位数字是随机数,就输出是幸运会员,否则就输出不是

package com.ym.pc;

import java.util.Random;
import java.util.Scanner;

public class Practise2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入一个4位会员卡号");
        int number = input.nextInt();
        int baiwei = number / 100 % 10;
        Random r = new Random();
        int a = (int) r.nextInt(10);
        if (baiwei == a) {
            System.out.println("该用户是幸运会员");
        } else {
            System.out.println("该用户不是幸运会员");
        }

    }

}

 

3.已知函数,输入x的值,输出对应的y的值.

        x + 3 ( x > 0 )

y =  0 ( x = 0 )

        x*2 –1 ( x < 0 )

 

package com.ym.pc;

import java.util.Scanner;

public class Practise3 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入x的值");
        int x = input.nextInt();
        int y;
        if (x > 0) {
            y = x + 3;

        } else if (x == 0) {
            y = 0;

        } else {
            y = x * 2 - 1;

        }
        System.out.println("y的值是" + y);

    }

}

 

4.输入三个数,判断能否构成三角形(任意两边之和大于第三边).

package com.ym.pc;

import java.util.Scanner;

public class Practise {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入三个数");
        int x = input.nextInt();
        int y = input.nextInt();
        int z = input.nextInt();
        if (x + y > z && x + z > y && y + z > x) {
            System.out.println("可以构成三角形");
        } else {
            System.out.println("不能构成三角形");
        }

    }

}

 

二.作业

1.输入年份月份,输出该月的天数(闰年2月29天,条件参考上机练习1).

package com.ym.ho;

import java.util.Scanner;

public class HomeWork1 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入年份月份");
        int year = input.nextInt();
        int month = input.nextInt();
        if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8
                || month == 10 || month == 12) {
            System.out.println("该月有31天");
        } else if (month == 4 || month == 6 || month == 9 || month == 11) {
            System.out.println("该月有30天");
        } else if (year % 2 == 0 && year % 100 != 0 || year % 400 == 0) {
            System.out.println("该月有29天");
        } else {
            System.out.println("该月有28天");
        }

    }

}

 

2.给定一个成绩a，使用switch结构求出a的等级

A：90-100，B：80-89，C：70-79，D：60-69，E：0~59

 

package com.ym.ho;

import java.util.Scanner;

public class HomeWork2 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入一个成绩");
        int a = input.nextInt();
        switch (a / 10) {
        case 9:
        case 10:
            System.out.println("A");
            break;
        case 8:
            System.out.println("B");
            break;
        case 7:
            System.out.println("C");
            break;
        case 6:
            System.out.println("D");
            break;
        default:
            System.out.println("E");
        }

    }

}

3.输入一个数字,判断是一个奇数还是偶数.

package com.ym.ho;

import java.util.Scanner;

public class HomeWork3 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("请输入一个数字");
        int m = input.nextInt();
        if (m % 2 == 0) {
            System.out.println("该数是一个偶数");
        }
        else if (m%2!=0){
            System.out.println("该数是一个奇数");
        }
        else{
            System.out.println("该数既不是奇数也不是偶数");
        }
    }

}

 

 

4.编写程序,判断一个变量x的值,如果是1,输出x=1,如果是5,输出x=5,如果是10,输出x=10,除了以上几个值,都输出x=none.

package com.ym.ho;

import java.util.Scanner;

public class HomeWork4 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入x的值");
        int x = input.nextInt();
        if (x == 1) {
            System.out.println("x=1");
        } else if (x == 5) {
            System.out.println("x=5");
        } else if (x == 10) {
            System.out.println("x=10");
        } else {
            System.out.println("x=none");
        }
    }

}

 

5.判断一个数字是否能被5和6同时整除(打印能被5和6整除),或只能被5整除(打印能被5整除),或只能被6整除(打印能被6整除),不能被5或6整除(打印不能被5或6整除).

 

package com.ym.ho;

import java.util.Scanner;

public class HomeWork5 {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("随机输入一个数字");
        int x = input.nextInt();
        if (x % 5 == 0 && x % 6 == 0) {
            System.out.println("该数能被5和6整除");
        } else if (x % 5 == 0) {
            System.out.println("该数能被5整除");
        } else if (x % 6 == 0) {
            System.out.println("该数能被6整除");
        } else if (x % 5 != 0 || x % 6 != 0) {
            System.out.println("该数不能被5或6整除");
        } else {
            System.out.println("错误");
        }
    }

}