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ArrayMethods.java

@@ -33,31 +33,61 @@ public class ArrayMethods
   /**DESCRIPTION: */
   public static String arrayString(int[] a)
   {
-    return ""; //STUB to keep compiler happy
+    String result = "{ " + a[0];
+    //return ""; //STUB to keep compiler happy
+      for(int i = 1; i < a.length; i++) {
+         result += ", " + a[i];
+      }
+
+    result += " }";
+
+    return result;
   }
 
   /**DESCRIPTION: */
   public static void swap(int[] array, int a, int b)
   {
-
+    int temp = array[a];
+    array[a] = array[b];
+    array[b] = temp;
   }
-	
-	/**DESCRIPTION: */
+  
+  /**DESCRIPTION: */
   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+1; i < array.length; i++) {
+      if(minValue > array[i]) {
+        minValue = array[i];
+        minIndex = i;
+      }
+
+    }
+    return minIndex;
+
   }
 
-	/**DESCRIPTION: */
+  /**DESCRIPTION: */
   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: */
   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

@@ -9,6 +9,31 @@ public class Main
 {
   public static void main(String[] args)
   {
+    int[] values = {12, 16, 26, 42, 53, 77, 84};
+
+    System.out.println("Test :" + ArrayMethods.arrayString(values));
+
+    ArrayMethods.swap(values, 0, 6);
+    System.out.println("Test after swap (12and84):" + ArrayMethods.arrayString(values));
+
+    int[] numbers = {42, 16, 84, 12, 77, 26, 53};
+    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 before reversal:" + ArrayMethods.arrayString(numbers));
+
+    ArrayMethods.reverse(numbers);
+
+    System.out.println("Test after reversal:" + ArrayMethods.arrayString(numbers));
+
+    System.out.println("Test before sorting:" + ArrayMethods.arrayString(numbers));
+
+    ArrayMethods.selectionSort(numbers);
+
+    System.out.println("Test 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=18806281)
 # Lab 15 - Selection Sort + Array Methods
 
 **Implement the Selection Sort Algorithm Using Array Methods**