第二次作业

//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 hw;

import java.util.Scanner;

public class test {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner input = new Scanner(System.in);		
		System.out.print("请输入任意年份:");		
		int year = input.nextInt();		
		if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0){			
			System.out.println(year + "年是闰年");			
		}else{			
			System.out.println(year + "年不是闰年");			
		}
	}

}

　　

//2.输入一个4位会员卡号,如果百位数字是3的倍数,就输出是幸运会员,否则就输出不是.
package hw;

import java.util.Scanner;

public class test1 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner input = new Scanner(System.in);	
		System.out.print("请输入会员卡号:");	
		int num = input.nextInt();
		if (num >= 1000 && num <=9999) {			
            if(num / 100 % 10 % 3 == 0) {	
                System.out.println("您是幸运会员"); 
            }else {
            	System.out.println("您不是幸运会员");
            	}
        }else {
        	System.out.println("您的会员卡号有误");
        	}   
	}
}

　　

/*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 )
                      x2 –1  ( x < 0 )*/
package hw;

import java.util.Scanner;

public class test2 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner input = new Scanner(System.in);	
        System.out.print("请输入x的值:");
        int x = input.nextInt();
		int y;
		while( x > 0 ){
			y = x + 3;
			System.out.println("y的值为" + y);
			break;
		 }		
		while( x == 0 ){
			y = 0;
			System.out.println("y的值为" + y);
			break;
		 }
		while( x < 0 ){
			y = x * 2 - 1;
			System.out.println("y的值为" + y);
			break;
		 }
	}

}

　　

//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 hw;

import java.util.Scanner;

public class test3 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner input = new Scanner(System.in);	
        System.out.print("请输入第一条边:");
        int x = input.nextInt();
        System.out.print("请输入第二条边:");
        int y = input.nextInt();
        System.out.print("请输入第三条边:");
        int z = input.nextInt();
        if( x + y >= z  &&  x + z >= y  &&  y + z >= x){
            System.out.println("这三条边能构成三角形");
        }else {
            System.out.println("这三条边不能构成三角形");
            }
	}
}