How to finish this program?

Question

I realize from reading the rules that we are not supposed to post entire assignments so I'll post the code and only ask about the one part I need. The last part of the assignment is to:
"// while there is an activity,
// -print the one with earliest end time i.e. first one - call this A.
// -Delete all activities in the list that start before the end of the one printed.
// Note that this will include the first activity.
// You may do the deletion by shifting up by one notch all activities below
// the one to be deleted and then decrease the number of activities left by 1.
Here is the source code:
* Assignment #1
* The following program segement is for a program that reads a list
* of activities (activity-name start-time end-time). The times are
* entered and displayed in military time. After reading the input, it
* - echoes back the entered activities
* - displays the activities in increasing order of end times
* - and lastly displays the non-overlapping activities.
* To find the non-overlapping activities, it sorts the activity list in
* ascending order of end times, then prints the first activity in the
* sorted list. Next, all activities that start before the printed activity
* are deleted from the sorted list. Again from the remaining activities,
* the first one (i.e. the one that ends the soonest) is printed, and all
* activities that start before the end of this one are deleted. This process
* is repeated until all non-overlapping activities are printed.
* Your assignment is to complete the missing segments of the program
* so it completes the above task. You should only change the methods/segments
* you are asked to change. Do not change my own methods or other areas.
* You may test your program with the following data. Run the program twice.
6
sleep 0012 0100
shower 0050 0200
eat 700 0800
study 0530 0900
drive 0700 1000
lunch 1100 1200
* Data for the 2nd execution
5
sleep 0000 0700
brush_teeth 0700 0715
shower 0700 0730
eat 0630 0730
study 0710 0900
import java.util.Scanner ;
// tActivity class: for a single activity
class tActivity {
   // declare activity name, start and end times.
   private String name;
   private int startTime, endTime;
   // define a constructor for a new activity
   tActivity () {
       name=null; startTime=endTime=-1;
   // define methods for manipulating the data members.
   // readActivity: reads activity name, start and end times.
  public void read (Scanner input) {
       name = input.next();
       startTime = input.nextInt();
       endTime = input.nextInt();
   // printActivity: Prints the activity name, start and end times.
   public void print() {
       // convert to military time before printing
       String sTime=""+startTime, eTime=""+endTime;
       while (sTime.length() < 4) sTime = "0"+sTime;
       while (eTime.length () < 4) eTime = "0"+eTime;
System.out.printf("%-20s %6s %9s\n", name, sTime, eTime);
   // getStartTime: returns the activity startTime
   public int getStartTime() {
       return startTime;
   // getEndTime: returns the activity endTime
   public int getEndTime() {
       return endTime;
// tActivityList: for a list of activities
class tActivityList {
   private int nActivities;
   private tActivity[] list;
   // constructor for creating activity list
   tActivityList(int nActivities) {
       int i;
       this.nActivities = nActivities;
       list = new tActivity[nActivities];
       for (i=0; i < nActivities; i++) list=new tActivity();
// read the individual activities into the activity list
// YOU ARE TO COMPLETE THIS METHOD
public void read(Scanner scan) {
for (list.read[i];)
nActivities[sTime][eTime]=scan.nextInt();
// display the list of all activities - name, start and end times
// YOU ARE TO COMPLETE THIS METHOD
public void print() {
// sort activity list in ascending order of end times
// uses bubble sort
public void sort() {
tActivity temp;
boolean sorted;
int i, passes=0;
do {
sorted = true;
passes++;
for (i=0; i < nActivities-passes; i++) {
if (list[i].getEndTime() > list[i+1].getEndTime()) { // swap them
temp = list[i]; list[i]=list[i+1]; list[i+1]=temp;
sorted = false;
} while (!sorted);
// printNonOverlappingActivities:
// while there is an activity,
// -print the one with earliest end time i.e. first one - call this A.
// -Delete all activities in the list that start before the end of the one printed.
// Note that this will include the first activity.
// You may do the deletion by shifting up by one notch all activities below
// the one to be deleted and then decrease the number of activities left by 1.
// YOU ARE TO COMPLETE THIS METHOD
public void printNonOverlapping() {
int i,j,count=0;
tActivity temp;
System.out.println("\n\nTHIS IS THE LIST OF NON-OVERLAPPING ACTIVITIES\n"+
"-#- ---ACTIVITY NAME---- STARTTIME ENDTIME");
while (nActivities > 0) {
// print the first one
// -Delete all activities in the list that start before the end of the one printed.
// Note that this will include the first activity.
// You may do the deletion by shifting up by one notch all activities below
// the one to be deleted and then decrease the number of activities left by 1.
public class activities {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int nActivities;
System.out.print
("Enter the total number of activities: ");
nActivities = scan.nextInt();
tActivityList acts = new tActivityList(nActivities);
acts.read(scan);
System.out.println ("\n\nTHIS IS THE LIST OF ACTIVITIES ENTERED\n"+
"-#- ---ACTIVITY NAME---- STARTTIME ENDTIME");
acts.print();
acts.sort();
System.out.println ("\n\nTHIS IS THE LIST OF ACTIVITIES SORTED IN ASCENDING ORDER OF END TIMES\n"+
"-#- ---ACTIVITY NAME---- STARTTIME ENDTIME");
acts.print();
acts.printNonOverlapping();
The first two I think I can do with the read and print functions but I'm having trouble with the third part of the assignment. Does anybody have any suggestions as to how to at least start the third part?

Answer 1

That was trickier that I thought...
   * printNonOverlappingActivities prints activities which do not occur in the
   * same period as any other activity.
  public void printNonOverlapping() {
    if (nActivities == 0) {
      System.out.println("# The activities list is empty");
      return;
    Activity.printColumnHeadings();
    while (nActivities > 0) {
      // print the first one
      activities[0].print();
      // remember the end time of the one printed.
      int theEndTime = activities[0].getEndTime();
      // -Delete all activities in the list which start before the end of the
      //  one printed. Note that this will include the first activity.
      int i = 0;
      while ( i < this.nActivities ) {
        if (activities.getStartTime() < theEndTime) {
delete(i);
i = 0;
} else {
i++;
* deletes the activity at "index" from the activities.
public void delete(int index) {
for(int i=index; i<nActivities-1; i++) {
this.activities[i] = activities[i+1];
this.nActivities--;
It took me a while (about an hour) to figure out why it help printing the second row (shower)... you need the else i++; because the delete removes the top row... I think you could also do it by deleting the first row before going into the loop, but after remembering it's endTime.
Headmaster: I do wish you'd listen, Wymer, it's perfectly simple.
If you're not getting your hair cut, you don't have to move
your brother's clothes down to the lower peg, you simply
collect his note before lunch after you've done your scripture
prep when you've written your letter home before rest, move
your own clothes on to the lower peg, greet the visitors, and
report to Mr Viney that you've had your chit signed.cheers. keith.