Add Implementation of Tree Sort and Generic Type BST (#2638)

2026-03-13 08:40:43 +08:00 · 2021-10-20 21:08:21 +05:30
parent 3028cf58d8
commit ce53fee92f
3 changed files with 410 additions and 1 deletions
--- a/Sorts/TreeSort.java
+++ b/Sorts/TreeSort.java
@@ -0,0 +1,113 @@
+package Sorts;
+
+import static Sorts.SortUtils.print;
+
+import java.util.List;
+
+/**
+ * <h1> Implementation of the Tree Sort algorithm</h1>
+ *
+ * <p>
+ * Tree Sort: A sorting algorithm which constructs a Binary Search Tree
+ * using the unsorted data and then outputs the data by inorder traversal
+ * of the tree.
+ *
+ * Reference: https://en.wikipedia.org/wiki/Tree_sort
+ * </p>
+ *
+ * @author Madhur Panwar (https://github.com/mdrpanwar)
+ */
+public class TreeSort implements SortAlgorithm {
+
+  @Override
+  public <T extends Comparable<T>> T[] sort(T[] unsortedArray) {
+    return doTreeSortArray(unsortedArray);
+  }
+
+  @Override
+  public <T extends Comparable<T>> List<T> sort(List<T> unsortedList) {
+    return doTreeSortList(unsortedList);
+  }
+
+  private <T extends Comparable<T>> T[] doTreeSortArray(T[] unsortedArray) {
+    // create a generic BST tree
+    DataStructures.Trees.BSTRecursiveGeneric<T> tree = new DataStructures.Trees.BSTRecursiveGeneric<T>();
+
+    // add all elements to the tree
+    for(T element: unsortedArray) {
+      tree.add(element);
+    }
+
+    // get the sorted list by inorder traversal of the tree
+    List<T> sortedList = tree.inorderSort();
+
+    // add the elements back to the initial array
+    int i = 0;
+    for(T element: sortedList) {
+      unsortedArray[i++] = element;
+    }
+
+    // return the array
+    return unsortedArray;
+  }
+
+  private <T extends Comparable<T>> List<T> doTreeSortList(List<T> unsortedList) {
+    // create a generic BST tree
+    DataStructures.Trees.BSTRecursiveGeneric<T> tree = new DataStructures.Trees.BSTRecursiveGeneric<T>();
+
+    // add all elements to the tree
+    for(T element: unsortedList) {
+      tree.add(element);
+    }
+
+    // get the sorted list by inorder traversal of the tree and return it
+    return tree.inorderSort();
+  }
+
+  public static void main(String[] args) {
+    TreeSort treeSort = new TreeSort();
+
+    // ==== Integer Array =======
+    System.out.println("Testing for Integer Array....");
+    Integer[] a = { 3, -7, 45, 1, 343, -5, 2, 9 };
+    System.out.print(String.format("%-10s", "unsorted: "));
+    print(a);
+    a = treeSort.sort(a);
+    System.out.print(String.format("%-10s", "sorted: "));
+    print(a);
+    System.out.println();
+
+    // ==== Integer List =======
+    System.out.println("Testing for Integer List....");
+    List<Integer> intList = List.of(3, -7, 45, 1, 343, -5, 2, 9);
+    System.out.print(String.format("%-10s", "unsorted: "));
+    print(intList);
+    intList = treeSort.sort(intList);
+    System.out.print(String.format("%-10s", "sorted: "));
+    print(intList);
+    System.out.println();
+
+
+    // ==== String Array =======
+    System.out.println("Testing for String Array....");
+    String[] b = { "banana", "berry", "orange", "grape", "peach", "cherry", "apple", "pineapple" };
+    System.out.print(String.format("%-10s", "unsorted: "));
+    print(b);
+    b = treeSort.sort(b);
+    System.out.print(String.format("%-10s", "sorted: "));
+    print(b);
+    System.out.println();
+
+    // ==== String List =======
+    System.out.println("Testing for String List....");
+    List<String> stringList = List.of("banana", "berry", "orange", "grape", "peach", "cherry", "apple", "pineapple");
+    System.out.print(String.format("%-10s", "unsorted: "));
+    print(stringList);
+    stringList = treeSort.sort(stringList);
+    System.out.print(String.format("%-10s", "sorted: "));
+    print(stringList);
+
+  }
+
+}
+