public class ContainerTerminal {

	int rows;				// Crane lines
	int cols;				// Container sizes
	public Container[] rowHead;
	public Container[] colHead;

	public ContainerTerminal(int r, int c) {

		rows = r;
		cols = c;
		rowHead = new Container[r];
		colHead = new Container[c];
	}
	
	public void add(Container cont, int crane) {
		// Place container at end of crane line first
		Container current= rowHead[crane];
		cont.right= null;		// Container always placed at end of crane line
		Container prev= null;
		if (current == null)
			rowHead[crane] = cont;
		else {
			while (current != null) {
				prev= current;
				current = current.right;
			}
			prev.right= cont;
		}
		
		// Place container at end of size line by weight order
		int size= cont.size;
		int index= getSizeIndex(size);
		int weight= cont.weight;
		current= colHead[index];
		prev= null;
		if (current == null)
			colHead[index]= cont;
		else {
			while (current != null) {
				if (current.weight <= weight) {	// Insert cont before current
					cont.down= current;
					if (colHead[index] == current)	// Cont is first element in list
						colHead[index]= cont;
					else 
						prev.down= cont;
					return;
				}
				else {
					prev= current;
					current= current.down;
				}
			}
			// If we reach end of list, cont has greatest weight
			prev.down= cont;		// cont.down initialized to null already
			return;
		}
	}

	public Container getFirst(int crane) {
		return rowHead[crane];
	}
	
	public boolean remove(String ID) {
		// Look for container in crane list. Not guaranteed to be found
		Container remove= null;			// Reference to container to remove
		Container prevRight= null;		// Ref to previous container, whose right points to it
		int size= 0;
		int crane= -1;
		boolean found = false;
		for (int i=0; i < rowHead.length; i++) {	// Search thru all crane lines
			Container current= rowHead[i];
			prevRight = null; // reset the prevRight when starting a new row
			while (current != null) {
				if (current.id.equals(ID)) {
					remove= current;
					size= current.size;
					crane= i;
					found = true;
					break;		// Only breaks out of inner loop; would be better to break entire loop
				}
				else {
					prevRight= current;
					current= current.right;	
				}
			}
			if (found)
				break;
		}
		if (remove== null)
			return false;		// If while loop didn't break, ID not found

		// Find the container in the size list. Guaranteed to be found.
		int index= getSizeIndex(size);
		if (colHead[index]== remove)
			colHead[index]= remove.down;			// If only one container in size list
		else {
			Container currDown= colHead[index];
			while (currDown != null) {
				if (currDown.down== remove)
					break;
				else
					currDown= currDown.down;
			}
			currDown.down = remove.down;	// Splice around container in size list
			remove.down = null;
		}
		
		// Remove the container from crane list:
		// If prevRight is null, the record to remove must be the first one in the list
		// so we set rowHead to remove.right. Otherwise we set prevRight.right to remove.right:
		if (prevRight == null)
		{
			rowHead[crane]= remove.right;
			remove.right = null;
		}	
		else
		{
			prevRight.right= remove.right;
			remove.right = null;
		}
		return true;
	}

	public String printCraneLine(int crane) {
		String print = "Line for crane "+crane+" : ";
		Container current= rowHead[crane];
		while (current != null) {
			print += current.id+" ";
			current= current.right;
		}
		print += "\n";
		return print;
	}

	public String printContainerSizeLine (int size) {
		String print = "Line for container size "+size+" : ";
		int index= getSizeIndex(size);
		Container current= colHead[index];
		while (current != null) {
			print += "("+current.id+", "+current.weight+")";
			current= current.down;
		}
		print += "\n";
		return print;
	}
	
	public int getWeightBySize(int size) {
		int totalWeight= 0;
		int index= getSizeIndex(size);
		Container current= colHead[index];
		while (current != null) {
			totalWeight += current.weight;
			current= current.down;
		}
		return totalWeight;
	}
	
	public static int getSizeIndex(int size) {
		int index;
		if (size == 10)
			index= 0;
		else if (size == 20)
			index= 1;
		else		// Returns 2 even if invalid size entered; should throw exception
					// but it's too much work in this homework
			index= 2;
		return index;
	}
}