ex3_34.java

判断三角形

//3.34（显示月历）
import javax.swing.JOptionPane;
public class Ex3_34{
	public static void main (String[] args) {
     int year,month,week,numofday=0,i;
     year=Integer.parseInt(JOptionPane.showInputDialog("请输入年号:"));
     week=Integer.parseInt(JOptionPane.showInputDialog("输入该年第一天的星期:"));
     for(month=1;month<=12;month++){
     	switch(month){  //利用switch输出日历每个月的头部并计算得到每个月的天数
     	  case 1:System.out.println("          January "+year);
     	  numofday=31;  break;
     	  case 2:System.out.println("          Feburary "+year);
     	  if((year%400)==0||(year%4==0&&year%100!=0))
     	  numofday=29;
     	  else
     	  numofday=28;
     	  break;
     	  case 3:System.out.println("          March "+year);
     	  numofday=31;  break;
     	  case 4:System.out.println("          April "+year);
     	  numofday=30;  break;
     	  case 5:System.out.println("          May "+year);
     	  numofday=31;  break;
     	  case 6:System.out.println("          June "+year);
     	  numofday=30;  break;
     	  case 7:System.out.println("          July "+year);
     	  numofday=31;  break;
     	  case 8:System.out.println("          August "+year);
     	  numofday=31;  break;
     	  case 9:System.out.println("          September "+year);
     	  numofday=30;  break;
     	  case 10:System.out.println("          October "+year);
     	  numofday=31;  break;
     	  case 11:System.out.println("          November "+year);
     	  numofday=30;  break;
     	  case 12:System.out.println("          December "+year);
     	  numofday=31;  break;
     	}
     	System.out.println("----------------------------");
     	System.out.println(" Sun Mon Tue Wen Thu Fri Sat");//打印星期的头部
        for(i=0;i<week%7;i++)
           System.out.print("    ");
        for(i=1;i<=numofday;i++){
           if(i<10) System.out.print("   "+i);//对齐输出，使得一位数和两位数的输出结果能与前面星期的头部保持对齐
           else     System.out.print("  "+i);
           if((week+i)%7==0&&i!=numofday) System.out.println("\n"); //每输出7天进行换行
        }
        week=(week+i)%7;//根据上一个月第一天的星期计算出下个月第一天的星期
        System.out.println("\n");
     }
     System.exit(0);
}
}