Implemented Sentinel Loop.

src/Assignments/A2/Partition.java

@@ -59,7 +59,9 @@ Algorithm Design Block
 package Assignments.A2;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
+import java.util.Scanner;
 
 /**
  * Generates, if possible, two equal subsets of a given set of elements that are equal to each other.
@@ -72,6 +74,155 @@ public class Partition {
     private int[] set;
     private List<List<Integer>> subsets;
 
+    public static void main(String[] args) {
+        Partition program = new Partition();
+        program.start();
+    }
+
+    /**
+     * Used as the main sentential loop and loops until the exit option is selected.
+     *
+     * @precondition none
+     * @postcondition none
+     */
+    public void start() {
+        int option = this.getOption();
+        while (option != 4) {
+            this.executeOption(option);
+            option = this.getOption();
+        }
+    }
+
+    /**
+     * Performs the action related to the option that was chosen.
+     *
+     * @precondition none
+     * @postcondition the action was performed.
+     *
+     * @param option the option that was chosen.
+     */
+    private void executeOption(int option) {
+        if (option == 1) {
+            System.out.println("Please specify the size of the set.");
+            System.out.print("Size: ");
+            int newSize = this.getIntegerInput();
+            while (newSize < 1) {
+                System.out.println("Please enter a valid set size.");
+                System.out.print("Size: ");
+                newSize = this.getIntegerInput();
+            }
+            this.set = new int[newSize];
+        } if (option == 2) {
+            if (this.set == null) {
+                System.out.println("Please enter a set size and values ");
+                System.out.println();
+                return;
+            }
+            this.set = this.getValues();
+        } else {
+            if (this.set == null || this.set[0] == 0) {
+                System.out.println("Please enter a set size and values before executing the algorithm.");
+                System.out.println();
+                return;
+            }
+            this.performAlgorithm();
+        }
+        System.out.println();
+    }
+
+    /**
+     * Prints out the menu of options, asks for an input, and if that input is invalid it prints an error and
+     * prompts the user again for the input.
+     *
+     * @precondition none
+     * @postcondition none
+     *
+     * @return the option selected
+     */
+    private int getOption() {
+        this.displayMenu(); // Prints out the menu
+
+        // Asks for the option and begins the loop until a valid option is gathered.
+        System.out.print("Enter option number: ");
+        int input = getIntegerInput();
+        while (input < 1 || input > 4) { // Compares it to the valid options available.
+            System.out.println("\nPlease enter a valid input.");
+            System.out.print("Enter option number: ");
+            input = getIntegerInput();
+        }
+        System.out.println();
+        return input;
+    }
+
+    /**
+     * Displays the menu options.
+     *
+     * @precondition none
+     * @postcondition the menu is displayed.
+     */
+    private void displayMenu() {
+        System.out.println("-----------------MAIN MENU--------------");
+        System.out.println("1. Read set size (number of integers)");
+        System.out.println("2. Read set elements (integer values)");
+        System.out.println("3. Run algorithm and display outputs");
+        System.out.println("4. Exit program");
+        System.out.println();
+    }
+
+    /**
+     * Gets user input to a number. A prompt must be provided prior to running this method.
+     * If the input was not an integer/(unable to be autoboxed), returns -1.
+     *
+     * @precondition none
+     * @postcondition none
+     *
+     * @return the integer input, if invalid -1.
+     */
+    private int getIntegerInput() {
+        Scanner sc = new Scanner(System.in);
+        try {
+            String textInput = sc.nextLine();
+            return Integer.parseInt(textInput);
+        } catch (Exception e) {
+            return -1;
+        }
+    }
+
+    private int[] getValues() {
+        Scanner sc = new Scanner(System.in);
+        String input = null;
+        int[] values = new int[this.set.length];
+        System.out.println("Please enter a list of " + this.set.length + " positive values. (Ex. 34 35 21 23)");
+        while (values[0] == 0) {
+            System.out.print("Values: ");
+            input = sc.nextLine();
+            String[] stringRep = input.split(" ");
+
+            /* If the input values are not the same number as the set size */
+            if (stringRep.length != values.length || input.isEmpty() ) {
+                System.out.println("Please enter a valid list of " + this.set.length + " positive values. (Ex. 34 35 21 23)");
+                continue;
+            }
+
+            /* Attempts to convert each value from String to Integer. */
+            try {
+                for (int i = 0; i < values.length; i++) {
+                    values[i] = Integer.parseInt(stringRep[i]);
+                    if (values[i] < 1) {
+                        System.out.println("Please enter a valid list of " + this.set.length + " positive values. (Ex. 34 35 21 23)");
+                        Arrays.fill(values, 0);
+                        break;
+                    }
+                }
+            } catch (Exception e) {
+                System.out.println("Please enter a valid list of " + this.set.length + " positive values. (Ex. 34 35 21 23)");
+            }
+        }
+
+
+        return values;
+    }
+
     /**
      * Iterates through all the possible subsets generated by this.generateSubsets
      * and if a subset is found that is exactly half the size it sets the firstset
@@ -92,6 +243,7 @@ public class Partition {
          * Checks through every subset that was generated,
          * if a subset is found it sets the firstSubset to the found subset.
         */
+        generateSubsets();
         for (List<Integer> subset : subsets) {
             int subsetTotal = 0;
             for (int value : subset) {
@@ -134,12 +286,12 @@ public class Partition {
         String first = "{";
         String second = "{";
         if (firstSubset != null) {
-            for (int fvalues : firstSubset) {
+            for (int fValues : firstSubset) {
-                first += fvalues + ",";
+                first += fValues + ",";
             }
             first = first.substring(0, first.length()-1) + "}";
-            for (int svalues : secondSubset) {
+            for (int sValues : secondSubset) {
-                second += svalues + ",";
+                second += sValues + ",";
             }
             second = second.substring(0, second.length()-1) + "}";
         } else {
@@ -147,7 +299,7 @@ public class Partition {
             second = "of their elements found";
         }
 
-        System.out.println("Set size:               " + setSize);
+        System.out.println("Set size:               " + setSize + " integers");
         System.out.println("Integer values:         " + original);
         System.out.println("Disjoint subsets with same sum: " + first);
         System.out.println("                                " + second);