Implemented InterpolationSearch.java

src/Assignments/A3/InterpolationSearch.java

@@ -1,144 +1,96 @@
-// Name: Jonathan Turner
-// Class: CS 4306/01
-// Term: Spring 2024
-// Instructor: Dr. Haddad
-// Assignment: 3
-// IDE Name: IntelliJ
 package Assignments.A3;
 
-import java.util.Scanner;
-
-/**
- * This class is used to perform the interpolation search algorithm and display the results.
- *
- * @author Jonathan Turner
- * @version Spring 2024
- */
 public class InterpolationSearch {
 
-    /**
+    /** Holds if the value was found or not. */
-     * Starts the program.
+    private final boolean found;
-     * @param args the program arguments.
+    /** Holds the index of the key, -1 if not found. */
-     */
+    private final int index;
-    public static void main(String[] args) {
+    /** Holds the number of divisions used to perform the search. */
-        InterpolationSearch program = new InterpolationSearch();
+    private int divisions;
-        program.start();
-    }
 
     /**
-     * Used as the main sentential loop and loops until the exit option is selected.
+     * Accepts the values, performs the search, and assigns the fields to the corresponding output data.
+     * <p>
+     * This constructor accepts in the array to be searched and the key to be searched for. Based off of this,
+     * the method will perform some precondition checks to ensure the values are valid and then perform the
+     * search using the formula provided in the slide deck.
+     * </p>
      *
-     * @precondition none
+     * @param array The list of values being search through.
-     * @postcondition none
+     * @param key   The desired value being searched for.
+     *
+     * @throws IllegalArgumentException If the array is empty.
      */
-    public void start() {
+    public InterpolationSearch(int[] array, int key) {
-        int option = this.getOption();
+        /* Precondition for empty list. */
-        while (option != 4) {
+        if (array.length == 0) {
-            this.executeOption(option);
+            throw new IllegalArgumentException("The searched array cannot be empty.");
-            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) {
-
-        System.out.println();
-    }
-
-    /**
-     * Uses private fields to generate the number of subsets and comparisons.
-     *
-     * @precondition text != null && text != empty
-     * @postcondition the results are generated.
-     */
-    private void performAlgorithm() {
-
-    }
-
-    /**
-     * 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. Create, populate, and display array Values[]");
-        System.out.println("2. Read output table size");
-        System.out.println("3. Run interpolation search and display outputs");
-        System.out.println("4. Exit program");
-        System.out.println();
-    }
-
-    /**
-     * Gets a string and returns it. If the input is not valid it loops until valid.
-     *
-     * @precondition none
-     * @postcondition none
-     * @return a user-input text string.
-     */
-    private String getString() {
-        System.out.println("Specify a text to check number of substrings.");
-        System.out.print("Text: ");
-        Scanner sc = new Scanner(System.in);
-        String input = sc.nextLine();
-
-        while (input == null || input.isEmpty()) {
-            System.out.println("Please specify a valid text to check substrings.");
-            System.out.print("Text: ");
-            input = sc.nextLine();
         }
 
-        return input;
+        /* Precondition check to see if the list is size 1 element. */
+        if (array.length == 1) {
+            this.found = (array[0] == key);
+            this.divisions = 0;
+            this.index = (array[0] == key ? 0 : -1);
+            return;
+        }
+
+        /* Sets the default values for the search */
+        int low = 0;
+        int high = array.length-1;
+        this.divisions = 0;
+
+        /* Iterates as long as high is not less than low */
+        while (high >= low) {
+            int probe;
+
+            /* Checks if high is the same thing as low to prevent division by zero. */
+            if (high != low) {
+                probe = low + (((key - array[low]) * (high - low)) / (array[high] - array[low]));
+
+                /* This is here due to the fact that it is not always divided as there is only 1 element left. */
+                this.divisions++;
+            } else {
+                probe = high;
+            }
+            /* Checks if the key is less than the probe's value */
+            if (array[probe] > key) {
+                high = probe - 1;
+            } else if (array[probe] < key) { /* Checks if the key is greater than the probes value */
+                low = probe + 1;
+            } else { /* The key was found at the probes index. */
+                this.found = true;
+                this.index = probe;
+                return;
+            }
+        }
+        /* Sets the values if the key was not in the list. */
+        this.found = false;
+        this.index = -1;
     }
 
     /**
-     * Gets user input to a number. A prompt must be provided prior to running this method.
+     * Gets if the key was found.
-     * If the input was not an integer/(unable to be autoboxed), returns -1.
+     * @return if it was found.
-     *
-     * @precondition none
-     * @postcondition none
-     *
-     * @return the integer input, if invalid -1.
      */
-    private int getIntegerInput() {
+    public boolean isFound() {
-        Scanner sc = new Scanner(System.in);
+        return found;
-        try {
+    }
-            String textInput = sc.nextLine();
+
-            return Integer.parseInt(textInput);
+    /**
-        } catch (Exception e) {
+     * Gets the number of divisions it took for the search to conclude.
-            return -1;
+     * @return the number of divisions
-        }
+     */
+    public int getDivisions() {
+        return divisions;
+    }
+
+    /**
+     * Gets the index at which the key was found. If the key was not found it returns -1.
+     * @return the found index.
+     */
+    public int getIndex() {
+        return index;
     }
 }