//Time4.java
import java.text.DecimalFormat;  
public class Time4 {
   private int hour;    // 0 - 23
   private int minute;  // 0 - 59
   private int second;  // 0 - 59
   //5個(gè)重載的構(gòu)造函數(shù)
   public Time4(){ 
      setTime( 0, 0, 0 ); 
   }
   public Time4( int h ) { 
      setTime( h, 0, 0 ); 
   }
   public Time4( int h, int m ){ 
      setTime( h, m, 0 ); 
   }
   public Time4( int h, int m, int s ) { 
      setTime( h, m, s ); 
   }
   public Time4( Time4 time ){
      setTime( time.hour, time.minute, time.second );
   }
   public void setTime( int h, int m, int s ){
      hour = ( ( h >= 0 && h < 24 ) ? h : 0 );
      minute = ( ( m >= 0 && m < 60 ) ? m : 0 );
      second = ( ( s >= 0 && s < 60 ) ? s : 0 );
   }
   public String toUniversalString(){
      DecimalFormat twoDigits = new DecimalFormat( "00" );

      return twoDigits.format( hour ) + ":" +
         twoDigits.format( minute ) + ":" + twoDigits.format( second );
   }
   public String toStandardString(){
      DecimalFormat twoDigits = new DecimalFormat( "00" );
      return ( (hour == 12 || hour == 0) ? 12 : hour % 12 ) + ":" + 
         twoDigits.format( minute ) + ":" + twoDigits.format( second ) +
         ( hour < 12 ? " AM" : " PM" );
   }
}