module5/src/main/java/com/hithomelabs/princeton1/module5/AbstractCustomSorts.java

@@ -6,6 +6,9 @@ public abstract class AbstractCustomSorts<E> {
 
     // TODO: Implement this method
     public void exch(E[] arr, int j, int i) {
+        E temp = arr[i];
+        arr[i] = arr[j];
+        arr[j] = temp;
     }
 
     // TODO: Implement this method

module5/src/main/java/com/hithomelabs/princeton1/module5/Insertion.java

@@ -3,7 +3,13 @@ package com.hithomelabs.princeton1.module5;
 public class Insertion<E> extends AbstractCustomSorts<E> {
     @Override
     public void sort(E[] arr) {
-
+        for(int i=1; i<arr.length; i++){
+            int k = i;
+            for(int j=i-1; j>=0 && less((Comparable<E>) arr[k], arr[j]); j--){
+                exch(arr, k, j);
+                k = j;
+            }
+        }
     }
 }
 

module5/src/main/java/com/hithomelabs/princeton1/module5/Selection.java

@@ -7,7 +7,14 @@ package com.hithomelabs.princeton1.module5;
 public class Selection<E> extends AbstractCustomSorts<E>{
     @Override
     public void sort(E[] arr) {
-
+        for (int i = 0; i < arr.length; i++) {
+            int minIndex = i;
+            for(int j = i+1; j < arr.length; j++){
+                if(less((Comparable<E>) arr[j], arr[minIndex]))
+                    minIndex = j;
+            }
+            exch(arr, i, minIndex);
+        }
     }
 }
 

module5/src/main/java/com/hithomelabs/princeton1/module5/Shell.java

@@ -24,10 +24,29 @@ public class Shell<E> extends AbstractCustomSorts<E> {
  */
     @Override
     public void sort(E[] arr) {
+        MetaData metaData = new MetaData();
+        for(int i=arr.length/10; i>=0; i--){
+            hsort(arr, 3*i+1, metaData);
+        }
+        System.out.println("Array sorted (shell sort) with " + metaData.compares + " compares and " + metaData.swaps + " swaps");
     }
 
-    private int hsort(E[] arr, int h, MetaData metadata) {
-        return 0;
+    private void hsort(E[] arr, int h, MetaData metadata) {
+        for(int i=0; i<arr.length; i=i+h){
+            int k = i;
+            for(int j=i-h; j>=0; j=j-h){
+                metadata.compares++;
+                if(less((Comparable<E>) arr[k], arr[j])){
+                    exch(arr, k, j);
+                    k = j;
+                    metadata.swaps++;
+                }
+                else{
+                    break;
+                }
+
+            }
+        }
     }
     /*
      ! sample implementation of insertion sort as h-sort of h = 1
@@ -36,7 +55,7 @@ public class Shell<E> extends AbstractCustomSorts<E> {
     public void insertionSort(E[] arr){
         MetaData metaData = new MetaData();
         int h = 1;
-        h = hsort(arr, h, metaData);
+        hsort(arr, h, metaData);
         System.out.println("Array sorted (insertion sort) with " + metaData.compares + " compares and " + metaData.swaps + " swaps");
     }