Generic Tree Algorithm
The Generic Tree Algorithm (GTA) is a versatile technique used in computer science to address various tree-based problems, such as tree traversals, search, insertion, deletion, and other tree-related operations. It uses a data structure called a generic tree, which is a non-linear hierarchical structure consisting of nodes with an arbitrary number of child nodes. Unlike binary trees, where each node can have at most two children, a generic tree can have any number of children. This makes the generic tree algorithm suitable for a wide range of applications, such as representing hierarchical relations between elements, organizing data in a multi-level structure, and modeling complex systems.
The fundamental principle behind the generic tree algorithm is the recursive traversal of the tree structure. This can be done using depth-first search (DFS) or breadth-first search (BFS) methods, depending on the specific problem being tackled. During the traversal, the algorithm processes each node in the tree and performs the required operations, such as updating values, inserting new nodes, or removing nodes. In addition to traversal, the generic tree algorithm can also be augmented with various heuristics, optimization techniques, or custom data processing functions to cater to specific use cases. The flexibility and adaptability of the generic tree algorithm make it widely applicable in various fields of computer science, including artificial intelligence, data mining, natural language processing, and computer graphics.
package DataStructures.Trees;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Scanner;
/**
* A generic tree is a tree which can have as many children as it can be
* It might be possible that every node present is directly connected to
* root node.
* <p>
* In this code
* Every function has two copies: one function is helper function which can be called from
* main and from that function a private function is called which will do the actual work.
* I have done this, while calling from main one have to give minimum parameters.
*/
public class GenericTree {
private class Node {
int data;
ArrayList<Node> child = new ArrayList<>();
}
private Node root;
private int size;
public GenericTree() { //Constructor
Scanner scn = new Scanner(System.in);
root = create_treeG(null, 0, scn);
}
private Node create_treeG(Node node, int childindx, Scanner scn) {
// display
if (node == null) {
System.out.println("Enter root's data");
} else {
System.out.println("Enter data of parent of index " + node.data + " " + childindx);
}
// input
node = new Node();
node.data = scn.nextInt();
System.out.println("number of children");
int number = scn.nextInt();
for (int i = 0; i < number; i++) {
Node child = create_treeG(node, i, scn);
size++;
node.child.add(child);
}
return node;
}
/**
* Function to display the generic tree
*/
public void display() { //Helper function
display_1(root);
}
private void display_1(Node parent) {
System.out.print(parent.data + "=>");
for (int i = 0; i < parent.child.size(); i++) {
System.out.print(parent.child.get(i).data + " ");
}
System.out.println(".");
for (int i = 0; i < parent.child.size(); i++) {
display_1(parent.child.get(i));
}
}
/**
* One call store the size directly but if you are asked compute size this function to calculate
* size goes as follows
*
* @return size
*/
public int size2call() {
return size2(root);
}
public int size2(Node roott) {
int sz = 0;
for (int i = 0; i < roott.child.size(); i++) {
sz += size2(roott.child.get(i));
}
return sz + 1;
}
/**
* Function to compute maximum value in the generic tree
*
* @return maximum value
*/
public int maxcall() {
int maxi = root.data;
return max(root, maxi);
}
private int max(Node roott, int maxi) {
if (maxi < roott.data)
maxi = roott.data;
for (int i = 0; i < roott.child.size(); i++) {
maxi = max(roott.child.get(i), maxi);
}
return maxi;
}
/**
* Function to compute HEIGHT of the generic tree
*
* @return height
*/
public int heightcall() {
return height(root) - 1;
}
private int height(Node node) {
int h = 0;
for (int i = 0; i < node.child.size(); i++) {
int k = height(node.child.get(i));
if (k > h)
h = k;
}
return h + 1;
}
/**
* Function to find whether a number is present in the generic tree or not
*
* @param info number
* @return present or not
*/
public boolean findcall(int info) {
return find(root, info);
}
private boolean find(Node node, int info) {
if (node.data == info)
return true;
for (int i = 0; i < node.child.size(); i++) {
if (find(node.child.get(i), info))
return true;
}
return false;
}
/**
* Function to calculate depth of generic tree
*
* @param dep depth
*/
public void depthcaller(int dep) {
depth(root, dep);
}
public void depth(Node node, int dep) {
if (dep == 0) {
System.out.println(node.data);
return;
}
for (int i = 0; i < node.child.size(); i++)
depth(node.child.get(i), dep - 1);
return;
}
/**
* Function to print generic tree in pre-order
*/
public void preordercall() {
preorder(root);
System.out.println(".");
}
private void preorder(Node node) {
System.out.print(node.data + " ");
for (int i = 0; i < node.child.size(); i++)
preorder(node.child.get(i));
}
/**
* Function to print generic tree in post-order
*/
public void postordercall() {
postorder(root);
System.out.println(".");
}
private void postorder(Node node) {
for (int i = 0; i < node.child.size(); i++)
postorder(node.child.get(i));
System.out.print(node.data + " ");
}
/**
* Function to print generic tree in level-order
*/
public void levelorder() {
LinkedList<Node> q = new LinkedList<>();
q.addLast(root);
while (!q.isEmpty()) {
int k = q.getFirst().data;
System.out.print(k + " ");
for (int i = 0; i < q.getFirst().child.size(); i++) {
q.addLast(q.getFirst().child.get(i));
}
q.removeFirst();
}
System.out.println(".");
}
/**
* Function to remove all leaves of generic tree
*/
public void removeleavescall() {
removeleaves(root);
}
private void removeleaves(Node node) {
ArrayList<Integer> arr = new ArrayList<>();
for (int i = 0; i < node.child.size(); i++) {
if (node.child.get(i).child.size() == 0) {
arr.add(i);
// node.child.remove(i);
// i--;
} else
removeleaves(node.child.get(i));
}
for (int i = arr.size() - 1; i >= 0; i--) {
node.child.remove(arr.get(i) + 0);
}
}
}
