Java程序第四次作业

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.homework04;
import java.util.Scanner;

public class Assignment01 {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        if ((n % 4 == 0 && n % 100 != 0) || n % 400 == 0) {
            System.out.println("闰年");
        }
        else {
            System.out.println("不是");
        }
    }
}

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.homework04;

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

public class Assignment02 {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int card = s.nextInt();
        int target = card / 100 % 10;
        Random r = new Random();
        int n = r.nextInt(9);
//		System.out.println("target: " + target + "\nn: " + n);
        if (target == n) {
            System.out.println("获奖");
        }
        else {
            System.out.println("未获奖");
        }
    }
}

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.homework04;


import java.util.Scanner;


public class Assignment03 {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int x = s.nextInt();
        int y = 0;
        if (x > 0) {
            y = x + 3;
        }
        else if (x == 0) {
            y = 0;
        }
        else if (x < 0) {
            y = x * 2 - 1;
        }

        System.out.println(y);
    }
}

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.homework04;


import java.util.Scanner;

public class Assignment04 {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int a = s.nextInt();
        int b = s.nextInt();
        int c = s.nextInt();
        if (a + b > c && a + c > b && b + c > a) {
            System.out.println("ok");
        }
        else {
            System.out.println("no");
        }
    }
}

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.homework04;
import java.util.Scanner;

public class Assignment05 {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int year = s.nextInt();
        int month = s.nextInt();
        if (month < 1 || month > 12) {
            return;
        }
        if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
            if (month == 2) {
                System.out.println(29);
                return;
            }
        }
        if (month == 2) {
            System.out.println(28);
        }
        else if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) {
            System.out.println(31);
        }
        else if (month == 4 || month == 6 || month == 9 || month == 11) {
            System.out.println(30);
        }
    }
}

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.homework04;


import java.util.Scanner;

public class Assignment06 {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);

        int grade = s.nextInt();
        if (grade < 0) {
            return;
        }
        int n = grade / 10;
        switch (n) {
            case 9:
                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");
        }
    }
}

输入一个数字，判断是一个奇数还是偶数

package com.homework04;


import java.util.Scanner;


public class Assignment07 {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        if (n % 2 == 0) {
            System.out.println("偶数");
        }
        else {
            System.out.println("奇数");
        }
    }
}

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.homework04;

public class Assignment08 {
    public static void main(String[] args) {
        int x = 1;
        if (x == 1 || x == 5 || x == 10) {
            System.out.println("x = " + x);
        }
        else {
            System.out.println("x = none");
        }
    }
}

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.homework04;

public class Assignment09 {
    public static void main(String[] args) {
        int n = 60;
        if (n % 5 == 0) {
            if (n % 6 == 0) {
                System.out.println("能被5和6整除");
            }
            else {
                System.out.println("能被5整除");
            }
        }
        else {
            if (n % 6 == 0) {
                System.out.println("能被6整除");
            }
            else {
                System.out.println("不能被5或6整除");
            }
        }
    }
}