Lab 5

Description:  This is a java application to demonstrate the use of data structures. The user inputs data and the program displays the data back in unsorted, sorted,  reversed, and set form. A LinkedList is used for the unsorted and sorted forms. The reverse form is implemented with a Stack and the set form (which is also sorted) is implemented with a TreeSet.

Code:

package jwarren.lab5;

import java.util.Collections;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Stack;
import java.util.TreeSet;

public class DataStructuresDemoApp {

	@SuppressWarnings("unchecked")
	public static void main(String args[]) {

		Scanner in = new Scanner(System.in);
		LinkedList<?> list;
		Stack<?> stack;
		TreeSet<?> tree;

		int menuSelection = 0;
		int elementCount = 0;
		String dataType;
		boolean error = true;

		String str;
		Integer intVal;
		Double realVal;

		System.out.println("What type of data do you wish to process?");
		System.out.println("1 - Text");
		System.out.println("2 - Integers");
		System.out.println("3 - Real Numbers");
		System.out.print(">");
		while (error) {
			try {

				menuSelection = in.nextInt();
				if (menuSelection < 1 || menuSelection > 3) {
					System.err.println("Please enter a value between 1 and 3");
					error = true;
				}

				else {
					error = false;
				}
			} catch (Exception e) {
				System.err.println("Please enter a numerical value");
				in.next();
			}
		}

		switch (menuSelection) {

		case 1:
			dataType = "word";
			list = new LinkedList();
			stack = new Stack();
			tree = new TreeSet();
			break;
		case 2:
			dataType = "integer";
			list = new LinkedList();
			stack = new Stack();
			tree = new TreeSet();
			break;
		default:
			dataType = "number";
			list = new LinkedList();
			stack = new Stack();
			tree = new TreeSet();
		}
		System.out.println("How many " + dataType + "s will you enter?");
		error = true;
		while (error) {
			try {
				elementCount = in.nextInt();
				if (elementCount < 0) {
					System.err.println("Please enter a non-negative value");
					error = true;
				} else {
					error = false;
				}
			} catch (Exception e) {
				System.err.println("Please enter a numerical value");
				in.next();
				error = true;
			}
		}

		for (int i = 0; i < elementCount; i++) {

			System.out.print("Enter " + dataType + " #" + (i + 1) + ":");
			error = true;
			while (error) {
				try {
					if (menuSelection == 1) {
						str = in.next();
						((LinkedList) list).add(str);
						((Stack) stack).push(str);
						((TreeSet) tree).add(str);
					}

					else if (menuSelection == 2) {
						intVal = in.nextInt();
						((LinkedList) list).add(intVal);
						((Stack) stack).push(intVal);
						((TreeSet) tree).add(intVal);
					}

					else if (menuSelection == 3) {
						realVal = in.nextDouble();
						((LinkedList) list).add(realVal);
						((Stack) stack).push(realVal);
						((TreeSet) tree).add(realVal);
					}
					error = false;
				} catch (Exception e) {
					System.err.println("Invalid input for type: " + dataType);
					in.next();
					error = true;
				}
			}
		}

		// Print container
		PrintCollections(menuSelection, list, stack, tree);

		in.close();
	}

	@SuppressWarnings("unchecked")
	private static void PrintCollections(int choice, LinkedList<?> list,
			Stack<?> stack, TreeSet<?> tree) {

		String str;
		Integer intVal;
		Double realVal;
		if (choice == 1) {

			System.out.print("Printing collection using list: ");
			for (String s : (LinkedList) list) {
				System.out.print(s + " ");
			}
			System.out.println();
			System.out.print("Printing collection using stack: ");
			int size = ((Stack) stack).size();
			for (int i = 0; i < size; i++) {
				str = ((Stack) stack).pop();
				System.out.print(str + " ");
			}
			System.out.println();
			System.out.print("Printing collection using sorted linked list: ");
			Collections.sort(((LinkedList)list));
			for(String s : (LinkedList)list){
				System.out.print(s + " ");
			}
			System.out.println();
			System.out.print("Printing collection using tree: ");
			for (String s : (TreeSet) tree) {
				System.out.print(s + " ");
			}
		}

		else if (choice == 2) {
			System.out.print("Printing collection using list: ");
			for (Integer i : (LinkedList) list) {
				System.out.print(i + " ");
			}
			System.out.println();
			System.out.print("Printing collection using stack: ");
			int size = ((Stack) stack).size();
			for (int i = 0; i < size; i++) {
				intVal = ((Stack) stack).pop();
				System.out.print(intVal + " ");
			}
			System.out.println();
			System.out.print("Printing collection using sorted linked list: ");
			Collections.sort(((LinkedList)list));
			for(Integer i : (LinkedList)list){
				System.out.print(i + " ");
			}
			System.out.println();
			System.out.print("Printing collection using tree: ");
			for (Integer i : (TreeSet) tree) {
				System.out.print(i + " ");
			}
		}

		else if (choice == 3) {
			System.out.print("Printing collection using list: ");
			for (Double d : (LinkedList) list) {
				System.out.print(d + " ");
			}
			System.out.println();
			System.out.print("Printing collection using stack: ");
			int size = ((Stack) stack).size();
			for (int i = 0; i < size; i++) {
				realVal = ((Stack) stack).pop();
				System.out.print(realVal + " ");
			}
			System.out.println();
			System.out.print("Printing collection using sorted linked list: ");
			Collections.sort(((LinkedList)list));
			for(Double d : (LinkedList)list){
				System.out.print(d + " ");
			}
			System.out.println();
			System.out.print("Printing collection using tree: ");
			for (Double d : (TreeSet) tree) {
				System.out.print(d + " ");
			}
		}
	}
}

Screenshots: