From 71a8a7aaedc803acc15248841f42306ba18e34c2 Mon Sep 17 00:00:00 2001
From: simon <simon@bussmann.es>
Date: Thu, 16 Jul 2020 15:06:14 +0200
Subject: [PATCH] added a BinaryTree

---
 TicTacToe - MinMax/src/BinaryTree.java   | 225 +++++++++++++++++++++++
 TicTacToe - MinMax/src/minmax_pseudo.txt |   9 +
 2 files changed, 234 insertions(+)
 create mode 100644 TicTacToe - MinMax/src/BinaryTree.java
 create mode 100644 TicTacToe - MinMax/src/minmax_pseudo.txt

diff --git a/TicTacToe - MinMax/src/BinaryTree.java b/TicTacToe - MinMax/src/BinaryTree.java
new file mode 100644
index 0000000..e5f6c4f
--- /dev/null
+++ b/TicTacToe - MinMax/src/BinaryTree.java	
@@ -0,0 +1,225 @@
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.Stack;
+
+public class BinaryTree {
+
+    Node root;
+
+    public void add(int value) {
+        root = addRecursive(root, value);
+    }
+
+    private Node addRecursive(Node current, int value) {
+
+        if (current == null) {
+            return new Node(value);
+        }
+
+        if (value < current.value) {
+            current.left = addRecursive(current.left, value);
+        } else if (value > current.value) {
+            current.right = addRecursive(current.right, value);
+        }
+
+        return current;
+    }
+
+    public boolean isEmpty() {
+        return root == null;
+    }
+
+    public int getSize() {
+        return getSizeRecursive(root);
+    }
+
+    private int getSizeRecursive(Node current) {
+        return current == null ? 0 : getSizeRecursive(current.left) + 1 + getSizeRecursive(current.right);
+    }
+
+    public boolean containsNode(int value) {
+        return containsNodeRecursive(root, value);
+    }
+
+    private boolean containsNodeRecursive(Node current, int value) {
+        if (current == null) {
+            return false;
+        }
+
+        if (value == current.value) {
+            return true;
+        }
+
+        return value < current.value
+                ? containsNodeRecursive(current.left, value)
+                : containsNodeRecursive(current.right, value);
+    }
+
+    public void delete(int value) {
+        root = deleteRecursive(root, value);
+    }
+
+    private Node deleteRecursive(Node current, int value) {
+        if (current == null) {
+            return null;
+        }
+
+        if (value == current.value) {
+            // Case 1: no children
+            if (current.left == null && current.right == null) {
+                return null;
+            }
+
+            // Case 2: only 1 child
+            if (current.right == null) {
+                return current.left;
+            }
+
+            if (current.left == null) {
+                return current.right;
+            }
+
+            // Case 3: 2 children
+            int smallestValue = findSmallestValue(current.right);
+            current.value = smallestValue;
+            current.right = deleteRecursive(current.right, smallestValue);
+            return current;
+        }
+        if (value < current.value) {
+            current.left = deleteRecursive(current.left, value);
+            return current;
+        }
+
+        current.right = deleteRecursive(current.right, value);
+        return current;
+    }
+
+    private int findSmallestValue(Node root) {
+        return root.left == null ? root.value : findSmallestValue(root.left);
+    }
+
+    public void traverseInOrder(Node node) {
+        if (node != null) {
+            traverseInOrder(node.left);
+            visit(node.value);
+            traverseInOrder(node.right);
+        }
+    }
+
+    public void traversePreOrder(Node node) {
+        if (node != null) {
+            visit(node.value);
+            traversePreOrder(node.left);
+            traversePreOrder(node.right);
+        }
+    }
+
+    public void traversePostOrder(Node node) {
+        if (node != null) {
+            traversePostOrder(node.left);
+            traversePostOrder(node.right);
+            visit(node.value);
+        }
+    }
+
+    public void traverseLevelOrder() {
+        if (root == null) {
+            return;
+        }
+
+        Queue<Node> nodes = new LinkedList<>();
+        nodes.add(root);
+
+        while (!nodes.isEmpty()) {
+
+            Node node = nodes.remove();
+
+            System.out.print(" " + node.value);
+
+            if (node.left != null) {
+                nodes.add(node.left);
+            }
+
+            if (node.right != null) {
+                nodes.add(node.right);
+            }
+        }
+    }
+
+
+    public void traverseInOrderWithoutRecursion() {
+        Stack<Node> stack = new Stack<Node>();
+        Node current = root;
+        stack.push(root);
+        while(! stack.isEmpty()) {
+            while(current.left != null) {
+                current = current.left;
+                stack.push(current);
+            }
+            current = stack.pop();
+            visit(current.value);
+            if(current.right != null) {
+                current = current.right;
+                stack.push(current);
+            }
+        }
+    }
+
+    public void traversePreOrderWithoutRecursion() {
+        Stack<Node> stack = new Stack<Node>();
+        Node current = root;
+        stack.push(root);
+        while(! stack.isEmpty()) {
+            current = stack.pop();
+            visit(current.value);
+
+            if(current.right != null)
+                stack.push(current.right);
+
+            if(current.left != null)
+                stack.push(current.left);
+        }
+    }
+
+    public void traversePostOrderWithoutRecursion() {
+        Stack<Node> stack = new Stack<Node>();
+        Node prev = root;
+        Node current = root;
+        stack.push(root);
+
+        while (!stack.isEmpty()) {
+            current = stack.peek();
+            boolean hasChild = (current.left != null || current.right != null);
+            boolean isPrevLastChild = (prev == current.right || (prev == current.left && current.right == null));
+
+            if (!hasChild || isPrevLastChild) {
+                current = stack.pop();
+                visit(current.value);
+                prev = current;
+            } else {
+                if (current.right != null) {
+                    stack.push(current.right);
+                }
+                if (current.left != null) {
+                    stack.push(current.left);
+                }
+            }
+        }
+    }
+
+    private void visit(int value) {
+        System.out.print(" " + value);
+    }
+
+    class Node {
+        int value;
+        Node left;
+        Node right;
+
+        Node(int value) {
+            this.value = value;
+            right = null;
+            left = null;
+        }
+    }
+}
\ No newline at end of file
diff --git a/TicTacToe - MinMax/src/minmax_pseudo.txt b/TicTacToe - MinMax/src/minmax_pseudo.txt
new file mode 100644
index 0000000..f2ec103
--- /dev/null
+++ b/TicTacToe - MinMax/src/minmax_pseudo.txt	
@@ -0,0 +1,9 @@
+Variables:
+player, board, search_depth
+
+Data_structure:
+BinaryTree
+
+Loops:
+recursion
+    for-loop