A tree is a hierarchical data structure in which data is stored in the form of nodes, which are connected by edges. Trees are non-linear data structures compared to arrays, linked lists, stacks, and queues. The most basic terms used in the tree data structure are node, root node, parent node, child node, leaf node, internal node, subtree, descendant, ancestor node, degree, and level of the node.

**Types of Trees in Data Structure:**

- General Tree
- Binary Tree
- Binary Search Tree
- AVL Tree
- B-Tree
- Splay Tree
- Red Black Tree
- Treap

**Advantages of Trees:**

- Tree is a hierarchical data storage system.
- Trees provide a flexible way to move data around with minimal effort.
- Tree reflects structural relationships in the data.
- It allows faster insertion, deletion, and searching operations on trees.

**Applications of Trees:**

- Folders and organizational structures are stored in a natural hierarchical data structure.
- It is used to organize data for efficient insertion, deletion, and searching operations.
- The tree data structure is also used to store data in the router’s routing tables.
- Heap is a tree data structure implemented using arrays and used to implement priority queues.
- Trie is a special kind of tree used to implement a dictionary.
- B-Tree and B+Tree are tree data structures used to implement indexing in databases.

The following section contains various programs on Trees, Binary Tree, Binary Search Tree, Expression Tree, AVL Tree, Tree Traversal, and KD Trees. Each sample program includes a program description, Java code, and program output. All examples have been compiled and tested on Windows and Linux systems.

**Here is the listing of Java programming examples on Trees:**

- Java Programs on Binary Tree
- Java Programs on Binary Search Tree
- Java Programs on Trees
- Java Programs on Expression Tree
- Java Programs on AVL Tree
- Java Programs on Tree Traversal
- Java Programs on KD Tree

Program |
Description |

Binary Tree in Java | Java Program to Implement Binary Tree |

AA Tree in Java | Java Program to Implement AA Tree |

Cartesian Tree in Java | Java Program to Implement Cartesian Tree |

Weight Balanced Tree in Java | Java Program to Implement Weight Balanced Tree |

Pagoda in Java | Java Program to Implement Pagoda |

Red Black Tree in Java | Java Program to Implement Red Black Tree |

Splay Tree in Java | Java Program to Implement Splay Tree |

Treap in Java | Java Program to Implement Treap |

Threaded Binary Tree in Java | Java Program to Implement Threaded Binary Tree |

Rope in Java | Java Program to Implement Rope |

ScapeGoat Tree in Java | Java Program to Implement ScapeGoat Tree |

Double Order Traversal of Binary Tree in Java | Java Program to Implement Double Order Traversal of a Binary Tree |

Java Program to Check if Binary Tree is Subtree of Another Tree | Java Program to Check if a Binary Tree is Subtree of Another Binary Tree |

Program |
Description |

Binary Search Tree in Java | Java Program to Implement Binary Search Tree |

Self Balancing BST in Java | Java Program to Implement Self Balancing Binary Search Tree |

Insertion in BST in Java | Java Program to Perform Insertion in Binary Search Tree |

Deletion in BST in Java | Java Program to Perform Deletion in Binary Search Tree |

Java Program to Search an Element in BST | Java Program to Search an Element in a Binary Search Tree |

BST Min Element in Java | Java Program to Find the Minimum Value of Binary Search Tree |

Randomized BST in Java | Java Program to Implement Randomized Binary Search Tree |

BST Right and Left Rotation in Java | Java Program to Perform Right and Left Rotation on a Binary Search Tree |

Balanced Binary Tree in Java | Java Program to Create a Balanced Binary Tree of the Incoming Data |

Program |
Description |

Ternary Tree in Java | Java Program to Implement Ternary Tree |

Ternary Search Tree in Java | Java Program to Implement Ternary Search Tree |

Fenwick Tree in Java | Java Program to Implement Fenwick Tree |

Disjoint Set Data Structure in Java | Java Program to Implement Disjoint Set Data Structure |

Segment Tree in Java | Java Program to Implement Segment Tree |

Interval Tree in Java | Java Program to Implement Interval Tree |

Range Tree in Java | Java Program to Implement Range Tree |

Binomial Tree in Java | Java Program to Implement Binomial Tree |

Suffix Tree in Java | Java Program to Implement Suffix Tree |

Print only Odd Numbered Levels of a Tree in Java | Java Program to Print the Nodes at Odd Levels of a Tree |

Delete a Node in Tree without Recursion in Java | Java Program to Delete a Particular Node in a Tree Without Recursion |

Prufer Code in Java | Java Program to Create the Prufer Code for a Tree |

Program |
Description |

Expression Tree in Java | Java Program to Implement Expression Tree |

Create Expression Tree from Infix Expression in Java | Java Program to Create Expression Tree from Infix Expression |

Program |
Description |

AVL Tree in Java | Java Program to Implement AVL Tree |

BST is AVL Tree or Not in Java | Java Program to Check if a Given Binary Tree is an AVL Tree or Not |

AVL Tree Operations in Java | Java Program to Perform AVL Tree Operations |

Program |
Description |

Inorder Traversal using Recursion in Java | Java Program to Perform Inorder Traversal of a Binary Tree using Recursion |

Inorder Traversal without Recursion in Java | Java Program to Perform Inorder Traversal of a Binary Tree without using Recursion |

Preorder Traversal using Recursion in Java | Java Program to Perform Preorder Traversal of a Binary Tree using Recursion |

Preorder Traversal without Recursion in Java | Java Program to Perform Preorder Traversal of a Binary Tree without using Recursion |

Postorder Traversal using Recursion in Java | Java Program to Perform Postorder Traversal of a Binary Tree using Recursion |

Postorder Traversal without Recursion in Java | Java Program to Perform Postorder Traversal of a Binary Tree without using Recursion |

Program |
Description |

K-D Tree for 2 Dimensional Data in Java | Java Program to Construct K-D Tree for 2 Dimensional Data |

2 Dimensional K-D Tree Insertion in Java | Java Program to Perform Insertion in a 2 Dimensional K-D Tree |

Partial Key Search in K-D Tree in Java | Java Program to Perform Partial Key Search in a K-D Tree |

Searching in 2-Dimension K-D Tree in Java | Java Program to Perform Searching in a 2-Dimensional K-D Tree |

Find 3D Point Location using K-D Trees in Java | Java Program to Find Location of a Point Placed in Three Dimensions Using K-D Trees |