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ArrayMethods.java

@@ -1,8 +1,8 @@
 /********************************************
-*	AUTHOR:	<name>
-* COLLABORATORS: <names>
+*	AUTHOR:	Michelle
+* COLLABORATORS: None
 *	COURSE:	CS 111 Intro to CS I - Java
-*	LAST MODIFIED: <date>
+*	LAST MODIFIED: 5/20/25
 ********************************************/
 
 /********************************************
@@ -12,7 +12,6 @@
 *	Collection of useful methods for int arrays.
 *********************************************
 *	ALGORITHM:
-*	TODO: <Pseudocode for selection sort here>
 *********************************************
 
 /* UML CLASS DIAGRAM:
@@ -30,34 +29,87 @@
 
 public class ArrayMethods
 {
-  /**DESCRIPTION: */
+  /**DESCRIPTION: 
+   * Returns Arrays contents in String form
+   * 
+   * @param a int[] of values, must be >= 1 length
+   * 
+   * @return array contents in String, separated by commas
+  */
+
   public static String arrayString(int[] a)
   {
-    return ""; //STUB to keep compiler happy
+    String result = "{ " + a[0];
+    //concotenates on each int value
+    for(int i = 1; i < a.length; i++){
+      result += ", " + a[i];
+    }
+    result += " }";
+
+    return result;
   }
 
-  /**DESCRIPTION: */
+  /**DESCRIPTION: 
+   * Swaps two values in the array at the given indices
+   * 
+   * @param array int[] that will be modified
+   * @param a index of first element to swap (must be valid index!)
+   * @param b index of second element to swap (must be valid index!)
+  */
   public static void swap(int[] array, int a, int b)
   {
-
+    int temp = array[a];
+    array[a] = array[b];
+    array[b] = temp;
   }
 
-	/**DESCRIPTION: */
+	/**DESCRIPTION: 
+   * Finds index of min value of an array at start index 
+   * 
+   * @param array int[] to search 
+   * @param start index to begin search for min
+   * 
+   * @return index of min value, from start index to end of array
+  */
+
   public static int indexOfMin(int[] array, int startIndex)
   {
-    return 0; //STUB to keep compiler happy
+    int minValue = array[startIndex];
+    int minIndex = startIndex;
+
+    for(int i = startIndex; i < array.length; i++){
+      if(minValue > array[i]) {
+        minValue = array[i];
+        minIndex = i;
+      }
+    }
+    return minIndex;
   }
 
-	/**DESCRIPTION: */
+	/**DESCRIPTION: 
+   * 
+   * Reverses contents of array
+   * 
+   * @param int[] array will be changed into reverse order
+  */
   public static void reverse(int[] array)
   {
-
+    for(int i = 0; i < array.length/2; i++){
+       ArrayMethods.swap(array, i, array.length-1-i);
+    }
   }
 
-	/**DESCRIPTION: */
+	/**DESCRIPTION: 
+   * Sorts array in ascending order (least to greatest), using selection sort algorithm
+   * 
+   * @param array int[] 
+  */
   public static void selectionSort(int[] array)
   {
-
+    for(int i = 0; i < array.length-1; i++){
+      int indexMinValue = ArrayMethods.indexOfMin(array, i);
+      ArrayMethods.swap(array, i, indexMinValue);
+    }
   }
 
 }

Main.java

@@ -1,14 +1,41 @@
 /********************************************
-*	AUTHOR:	<name>
-* COLLABORATORS: <names>
+*	AUTHOR:	Nichelle Mendoza
+* COLLABORATORS: None
 *	COURSE:	CS 111 Intro to CS I - Java
-*	LAST MODIFIED:	<date>
+*	LAST MODIFIED:	5/20/25
 ********************************************/
 
 public class Main 
 {
   public static void main(String[] args)
   {
+    int[] values = { 12, 16, 26, 42, 53, 77, 84 };
 
+    System.out.println("TEST array contents " + 
+    ArrayMethods.arrayString(values));
+
+
+    ArrayMethods.swap(values, 0, 6);
+
+    System.out.println("TEST: array after swap of 12 and 84 = " + 
+    ArrayMethods.arrayString(values));
+
+    int[] numbers = {42, 16, 84, 12, 77, 26, 53, 96};
+    int minIndex1 = ArrayMethods.indexOfMin(numbers, 0);
+    int minIndex2 = ArrayMethods.indexOfMin(numbers, 4);
+
+    System.out.println("TEST: min indices should be 3 and 5, we got: " + minIndex1 + " and " + minIndex2);
+
+    System.out.println("TEST: array before reversal = " + ArrayMethods.arrayString(numbers));
+
+    ArrayMethods.reverse(numbers);
+
+    System.out.println("TEST: array after reversal = " + ArrayMethods.arrayString(numbers));
+
+    System.out.println("TEST: array before sorting = " + ArrayMethods.arrayString(numbers));
+
+    ArrayMethods.selectionSort(numbers);
+
+    System.out.println("TEST: array after sorting = " + ArrayMethods.arrayString(numbers));
   }
 }

README.md

@@ -1,3 +1,4 @@
+[![Open in Codespaces](https://classroom.github.com/assets/launch-codespace-2972f46106e565e64193e422d61a12cf1da4916b45550586e14ef0a7c637dd04.svg)](https://classroom.github.com/open-in-codespaces?assignment_repo_id=19591134)
 # Lab 15 - Selection Sort + Array Methods
 
 **Implement the Selection Sort Algorithm Using Array Methods**