Creating a tree with Left-Child Right-Sibling Representation
Left-Child Right-Sibling Representation is a different representation of an n-ary tree where instead of holding a reference to each and every child node, a node holds just two references, first a reference to it’s first child, and the other to it’s immediate next sibling. This new transformation not only removes the need of advance knowledge of the number of children a node has, but also limits the number of references to a maximum of two, thereby making it so much easier to code.
At each node, link children of same parent from left to right. Parent should be linked with only first child.
Examples:
Left Child Right Sibling tree representation
10
|
2 -> 3 -> 4 -> 5
| |
6 7 -> 8 -> 9
Prerequisite : Left-Child Right-Sibling Representation of Tree
Below is the implementation.
C++
// C++ program to create a tree with left child// right sibling representation.#include<bits/stdc++.h>using namespace std;struct Node{ int data; struct Node *next; struct Node *child;};// Creating new NodeNode* newNode(int data){ Node *newNode = new Node; newNode->next = newNode->child = NULL; newNode->data = data; return newNode;}// Adds a sibling to a list with starting with nNode *addSibling(Node *n, int data){ if (n == NULL) return NULL; while (n->next) n = n->next; return (n->next = newNode(data));}// Add child Node to a NodeNode *addChild(Node * n, int data){ if (n == NULL) return NULL; // Check if child list is not empty. if (n->child) return addSibling(n->child, data); else return (n->child = newNode(data));}// Traverses tree in depth first ordervoid traverseTree(Node * root){ if (root == NULL) return; while (root) { cout << " " << root->data; if (root->child) traverseTree(root->child); root = root->next; }}//Driver codeint main(){ /* Let us create below tree * 10 * / / \ \ * 2 3 4 5 * | / | \ * 6 7 8 9 */ // Left child right sibling /* 10 * | * 2 -> 3 -> 4 -> 5 * | | * 6 7 -> 8 -> 9 */ Node *root = newNode(10); Node *n1 = addChild(root, 2); Node *n2 = addChild(root, 3); Node *n3 = addChild(root, 4); Node *n4 = addChild(n3, 6); Node *n5 = addChild(root, 5); Node *n6 = addChild(n5, 7); Node *n7 = addChild(n5, 8); Node *n8 = addChild(n5, 9); traverseTree(root); return 0;} |
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Java
// Java program to create a tree with left child// right sibling representation. class GFG { static class NodeTemp { int data; NodeTemp next, child; public NodeTemp(int data) { this.data = data; next = child = null; } } // Adds a sibling to a list with starting with n static public NodeTemp addSibling(NodeTemp node, int data) { if(node == null) return null; while(node.next != null) node = node.next; return(node.next = new NodeTemp(data)); } // Add child Node to a Node static public NodeTemp addChild(NodeTemp node,int data) { if(node == null) return null; // Check if child is not empty. if(node.child != null) return(addSibling(node.child,data)); else return(node.child = new NodeTemp(data)); } // Traverses tree in depth first order static public void traverseTree(NodeTemp root) { if(root == null) return; while(root != null) { System.out.print(root.data + " "); if(root.child != null) traverseTree(root.child); root = root.next; } } // Driver code public static void main(String args[]) { /* Let us create below tree * 10 * / / \ \ * 2 3 4 5 * | / | \ * 6 7 8 9 */ // Left child right sibling /* 10 * | * 2 -> 3 -> 4 -> 5 * | | * 6 7 -> 8 -> 9 */ NodeTemp root = new NodeTemp(10); NodeTemp n1 = addChild(root,2); NodeTemp n2 = addChild(root,3); NodeTemp n3 = addChild(root,4); NodeTemp n4 = addChild(n3,6); NodeTemp n5 = addChild(root,5); NodeTemp n6 = addChild(n5,7); NodeTemp n7 = addChild(n5,8); NodeTemp n8 = addChild(n5,9); traverseTree(root); }}// This code is contributed by M.V.S.Surya Teja. |
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Python3
# Python3 program to create a tree with # left child right sibling representation. # Creating new Node class newNode: def __init__(self, data): self.Next = self.child = None self.data = data# Adds a sibling to a list with# starting with n def addSibling(n, data): if (n == None): return None while (n.Next): n = n.Next n.Next = newNode(data) return n.Next# Add child Node to a Node def addChild(n, data): if (n == None): return None # Check if child list is not empty. if (n.child): return addSibling(n.child, data) else: n.child = newNode(data) return n.child# Traverses tree in depth first order def traverseTree(root): if (root == None): return while (root): print(root.data, end = " ") if (root.child): traverseTree(root.child) root = root.Next# Driver code if __name__ == '__main__': # Let us create below tree # 10 # / / \ \ # 2 3 4 5 # | / | \ # 6 7 8 9 # Left child right sibling # 10 # | # 2 -> 3 -> 4 -> 5 # | | # 6 7 -> 8 -> 9 root = newNode(10) n1 = addChild(root, 2) n2 = addChild(root, 3) n3 = addChild(root, 4) n4 = addChild(n3, 6) n5 = addChild(root, 5) n6 = addChild(n5, 7) n7 = addChild(n5, 8) n8 = addChild(n5, 9) traverseTree(root) # This code is contributed by pranchalK |
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C#
// C# program to create a tree with left // child right sibling representation. using System;class GFG{public class NodeTemp{ public int data; public NodeTemp next, child; public NodeTemp(int data) { this.data = data; next = child = null; }}// Adds a sibling to a list with// starting with n public static NodeTemp addSibling(NodeTemp node, int data){ if (node == null) { return null; } while (node.next != null) { node = node.next; } return (node.next = new NodeTemp(data));}// Add child Node to a Node public static NodeTemp addChild(NodeTemp node, int data){ if (node == null) { return null; } // Check if child is not empty. if (node.child != null) { return (addSibling(node.child,data)); } else { return (node.child = new NodeTemp(data)); }}// Traverses tree in depth first order public static void traverseTree(NodeTemp root){ if (root == null) { return; } while (root != null) { Console.Write(root.data + " "); if (root.child != null) { traverseTree(root.child); } root = root.next; }}// Driver code public static void Main(string[] args){ /* Let us create below tree * 10 * / / \ \ * 2 3 4 5 * | / | \ * 6 7 8 9 */ // Left child right sibling /* 10 * | * 2 -> 3 -> 4 -> 5 * | | * 6 7 -> 8 -> 9 */ NodeTemp root = new NodeTemp(10); NodeTemp n1 = addChild(root, 2); NodeTemp n2 = addChild(root, 3); NodeTemp n3 = addChild(root, 4); NodeTemp n4 = addChild(n3, 6); NodeTemp n5 = addChild(root, 5); NodeTemp n6 = addChild(n5, 7); NodeTemp n7 = addChild(n5, 8); NodeTemp n8 = addChild(n5, 9); traverseTree(root);}}// This code is contributed by Shrikant13 |
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Output:
10 2 3 4 6 5 7 8 9
Level Order Traversal : The above code talks about depth first traversal. We can also do level order traversal of such representation.
C++
// C++ program to create a tree with left child// right sibling representation.#include <bits/stdc++.h>using namespace std;struct Node { int data; struct Node* next; struct Node* child;};// Creating new NodeNode* newNode(int data){ Node* newNode = new Node; newNode->next = newNode->child = NULL; newNode->data = data; return newNode;}// Adds a sibling to a list with starting with nNode* addSibling(Node* n, int data){ if (n == NULL) return NULL; while (n->next) n = n->next; return (n->next = newNode(data));}// Add child Node to a NodeNode* addChild(Node* n, int data){ if (n == NULL) return NULL; // Check if child list is not empty. if (n->child) return addSibling(n->child, data); else return (n->child = newNode(data));}// Traverses tree in level ordervoid traverseTree(Node* root){ // Corner cases if (root == NULL) return; cout << root->data << " "; if (root->child == NULL) return; // Create a queue and enque root queue<Node*> q; Node* curr = root->child; q.push(curr); while (!q.empty()) { // Take out an item from the queue curr = q.front(); q.pop(); // Print next level of taken out item and enque // next level's children while (curr != NULL) { cout << curr->data << " "; if (curr->child != NULL) { q.push(curr->child); } curr = curr->next; } }}// Driver codeint main(){ Node* root = newNode(10); Node* n1 = addChild(root, 2); Node* n2 = addChild(root, 3); Node* n3 = addChild(root, 4); Node* n4 = addChild(n3, 6); Node* n5 = addChild(root, 5); Node* n6 = addChild(n5, 7); Node* n7 = addChild(n5, 8); Node* n8 = addChild(n5, 9); traverseTree(root); return 0;} |
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Python3
# Python3 program to create a tree with# left child right sibling representationfrom collections import dequeclass Node: def __init__(self, x): self.data = x self.next = None self.child = None# Adds a sibling to a list with # starting with ndef addSibling(n, data): if (n == None): return None while (n.next): n = n.next n.next = Node(data) return n# Add child Node to a Nodedef addChild(n, data): if (n == None): return None # Check if child list is not empty if (n.child): return addSibling(n.child, data) else: n.child = Node(data) return n# Traverses tree in level orderdef traverseTree(root): # Corner cases if (root == None): return print(root.data, end = " ") if (root.child == None): return # Create a queue and enque root q = deque() curr = root.child q.append(curr) while (len(q) > 0): # Take out an item from the queue curr = q.popleft() #q.pop() # Print next level of taken out # item and enque next level's children while (curr != None): print(curr.data, end = " ") if (curr.child != None): q.append(curr.child) curr = curr.next# Driver codeif __name__ == '__main__': root = Node(10) n1 = addChild(root, 2) n2 = addChild(root, 3) n3 = addChild(root, 4) n4 = addChild(n3, 6) n5 = addChild(root, 5) n6 = addChild(n5, 7) n7 = addChild(n5, 8) n8 = addChild(n5, 9) traverseTree(root)# This code is contributed by mohit kumar 29 |
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Output:
10 2 3 4 5 6 7 8 9
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