uni/inf2220/hw2/Project.java

import java.util.ArrayList;
import java.util.TreeMap;
import java.util.Scanner;
import java.util.Arrays;
import java.io.File;

class Project {
	Task[] tasks;

	ArrayList<Task> findCycle() {
		for (Task t: tasks) {
			if (t.tasksWhichDepend.size() != 0)
				continue;

			ArrayList<Task> l = t.findCycle();
			if (l != null)
				return l;
		}
		return null;
	}

	void readFile(File f) throws Exception {
		Scanner s = new Scanner(f);

		int nlines = Integer.parseInt(s.nextLine());
		s.nextLine();

		this.tasks = new Task[nlines];
		int[][] taskDeps = new int[nlines][];

		int n = 0;
		while (s.hasNextLine()) {
			String line = s.nextLine();
			if (line.equals("")) continue;

			String[] parts = line.split("\\s+");

			Task t = new Task();

			// Set easy properties
			t.id = Integer.parseInt(parts[0]);
			t.name = parts[1].replace('-', ' ');
			t.time = Integer.parseInt(parts[2]);
			t.manpower = Integer.parseInt(parts[3]);

			// Remember all the IDs of the dependencies for
			// after all tasks are read
			taskDeps[t.id - 1] = new int[parts.length - 5];
			for (int i = 4; i < parts.length - 1; ++i) {
				taskDeps[t.id - 1][i - 4] = Integer.parseInt(parts[i]);
			}

			this.tasks[t.id - 1] = t;
			n += 1;
		}

		if (n != nlines) {
			throw new Exception("Expected "+nlines+" lines, got "+n);
		}

		// Find dependencies from IDs, and add them to the tasks
		for (int i = 0; i < this.tasks.length; ++i) {
			int[] deps = taskDeps[i];
			Task t = this.tasks[i];
			t.deps = new Task[deps.length];

			for (int j = 0; j < deps.length; ++j) {
				int depid = deps[j];
				Task dep = this.tasks[depid - 1];
				dep.tasksWhichDepend.add(t);
				t.deps[j] = dep;
			}
		}
	}

	void calcTimes() {
		for (Task t: this.tasks) {
			if (t.tasksWhichDepend.size() == 0 && t.earliestStart == -1)
				t.calcTimes();
		}
		for (Task t: this.tasks) {
			t.calcLatestStart();
		}
	}

	class TimeTasks {
		ArrayList<Task> starts = new ArrayList<>();
		ArrayList<Task> ends = new ArrayList<>();
		int time;

		TimeTasks(int time) {
			this.time = time;
		}
	}
	void printTimes(int manpower) {
		int maxTime = 0;
		for (Task t: this.tasks) {
			if (maxTime < t.earliestFinished)
				maxTime = t.earliestFinished;
		}

		// TreeMap because it keeps keys sorted
		TreeMap<Integer, TimeTasks> taskMap = new TreeMap<>();

		for (Task t: this.tasks) {
			if (taskMap.get(t.earliestStart) == null)
				taskMap.put(t.earliestStart, new TimeTasks(t.earliestStart));
			if (taskMap.get(t.earliestFinished) == null)
				taskMap.put(t.earliestFinished, new TimeTasks(t.earliestFinished));

			taskMap.get(t.earliestStart).starts.add(t);
			taskMap.get(t.earliestFinished).ends.add(t);
		}

		for (Integer key: taskMap.keySet()) {
			TimeTasks tt = taskMap.get(key);
			System.out.println("\nTime: "+tt.time);
			for (Task t: tt.starts) {
				System.out.println(
					"            "+
					"Starting: "+
					t.identify());
				manpower -= t.manpower;
			}
			for (Task t: tt.ends) {
				System.out.println(
					"            "+
					"Finished: "+
					t.identify());
				manpower += t.manpower;
			}
			System.out.println(
				"    "+
				"Current manpower: "+
				manpower);
		}

		System.out.println(
			"\n"+
			"**** Shortest possible project execution is "+
			maxTime+
			". ****");
	}

	void printTasks() {
		for (Task t: this.tasks) {
			System.out.println("");
			System.out.println("Task "+t.id+":");
			System.out.println("    Name: "+t.name);
			System.out.println("    Time: "+t.time);
			System.out.println("    Manpower: "+t.manpower);
			System.out.println("    Slack: "+t.slack);
			System.out.println("    Earliest Start: "+t.earliestStart);
			System.out.println("    Latest Start: "+t.latestStart);
			System.out.print  ("    Tasks which depend:");

			for (Task ts: t.tasksWhichDepend) {
				System.out.print(" "+ts.id);
			}
			System.out.println("");
		}
	}
}