Given a complete binary tree with N levels numbered [0, (N – 1 )] from root to the lowest level in decreasing order and having weights numbered between [1, 2N – 1] from the root to the last leaf node in the increasing order, the task for every node is to adjust the values of the levels of all nodes present in its left and right subtree based on the following condition:
- Increase the level of all the nodes of lighter subtree by the difference of their weights.
- Decrease the level of all the nodes of heavier subtree by the difference of their weights.
Examples:
Input:
1 / \ 2 3Output: 0 0 -2
Explanation:
The initial levels of the nodes {1,2,3} are {0,-1,-1} respectively.
The root node remains unchanged.
The weight of left subtree is 2 and the weight of the right subtree is 3.
So, the left subtree goes up by (3 – 2) = 1 level to 0.
The right subtree goes down by 1 level to -2.
Input:
1 / \ 2 3 / \ / \ 4 5 6 7Output: 0 4 -6 4 2 -6 -8
Explanation:
The initial levels of the nodes {1,2,3,4,5,6,7} are {0,-1,-1,-2,-2,-2,-2} respectively.
The root node remains unchanged.
The weight of the left subtree {2,4,5} is 11.
The weight of the right subtree {3,6,7} is 16.
Hence, all the nodes in left subtree move up by 5 while those in the right subtree moves down by 5.
Thus, the new levels of every node are:
Node 2: -1 + 5 = 4
Node 3: -1 – 5 = -6
Node 4,5: -2 + 5 = 3
Node 6,7: -2 – 5 = -7
Now, nodes 4,5 further based on the difference of their weights (5 -4 ) = 1.
Node 4: 3 + 1 = 4
Node 5: 3 – 1 = 2
Similarly, nodes 6,7 also get adjusted.
Node 6: -7 + 1 = -6
Node 7: -7 – 1 = -8
Hence, the final adjusted levels of all the nodes are 0 4 -6 4 2 -6 -8.
Approach: In order to solve this problem, we calculate the weights of the left (w_left) and right (w_right) subtrees for every node and store their difference K. Once calculated, we recursively increase the value of the level of all the nodes of its lighter subtree by K and decrease that of its heavier subtree by K from their respective current values. Once computed for all nodes, we display the final values of the level of every node.
Below code is the implementation of the above approach:
C++
// C++ Program to print updated levels// of each node of a Complete Binary Tree// based on difference in weights of subtrees #include <bits/stdc++.h>using namespace std;// Node for the given binary treestruct node { int weight; // stores the weight of node int level; // stores the level of node struct node* left; struct node* right; node(int w, int l) { this->weight = w; this->level = l; left = right = NULL; }};// Utility function to insert a node// in a tree rooted at rootstruct node* insert(struct node* root, int n_weight, int n_level, queue<node*>& q){ struct node* n = new node(n_weight, n_level); // if the tree is empty till now // make node n the root if (root == NULL) root = n; // If the frontmost node of // queue has no left child // make node n its left child // the frontmost node still // remains in the queue because // its right child is null yet else if (q.front()->left == NULL) { q.front()->left = n; } // Make node n the right child of // the frontmost node and remove // the front node from queue else { q.front()->right = n; q.pop(); } // push the node n into queue q.push(n); return root;}// Function to create a complete binary treestruct node* createTree(vector<int> weights, vector<int> levels){ // initialise the root node of tree struct node* root = NULL; // initialise a queue of nodes queue<node*> q; int n = weights.size(); for (int i = 0; i < n; i++) { /* keep inserting nodes with weight values from the weights vector and level values from the levels vector */ root = insert(root, weights[i], levels[i], q); } return root;}// Function to print final levels of nodesvoid printNodeLevels(struct node* root){ if (root == NULL) return; queue<node*> q; q.push(root); while (!q.empty()) { cout << q.front()->level << " "; if (q.front()->left != NULL) q.push(q.front()->left); if (q.front()->right != NULL) q.push(q.front()->right); q.pop(); } cout << endl;}// Function to find the weight of subtreeint findWeight(struct node* root){ // If the root node is null // then weight of subtree will be 0 if (root == NULL) return 0; return root->weight + findWeight(root->left) + findWeight(root->right);}// Function to compute new level// of the nodes based on the// difference of weight Kvoid changeLevels(struct node* root, int k){ if (root == NULL) return; // Change the level of root node root->level = root->level + k; // Recursively change the level of // left and right subtree changeLevels(root->left, k); changeLevels(root->right, k);}// Function to calculate weight of// the left and the right subtrees and // adjust levels based on their differencevoid adjustLevels(struct node* root){ // No adjustment required // when root is null if (root == NULL) return; // Find weights of left // and right subtrees int w_left = findWeight(root->left); int w_right = findWeight(root->right); // find the difference between the // weights of left and right subtree int w_diff = w_left - w_right; // Change the levels of nodes // according to weight difference at root changeLevels(root->left, -w_diff); changeLevels(root->right, w_diff); // Recursively adjust the levels // for left and right subtrees adjustLevels(root->left); adjustLevels(root->right);}// Driver codeint main(){ // Number of levels int N = 3; // Number of nodes int nodes = pow(2, N) - 1; vector<int> weights; // Vector to store weights of tree nodes for (int i = 1; i <= nodes; i++) { weights.push_back(i); } vector<int> levels; // Vector to store levels of every nodes for (int i = 0; i < N; i++) { // 2^i nodes are present at ith level for (int j = 0; j < pow(2, i); j++) { // value of level becomes negative // while going down the root levels.push_back(-1 * i); } } // Create tree with the// given weights and levels struct node* root = createTree(weights, levels); // Adjust the levels adjustLevels(root); // Display the final levels printNodeLevels(root); return 0;} |
Java
// Java Program to print updated levels// of each node of a Complete Binary Tree// based on difference in weights of subtreesimport java.util.ArrayList;import java.util.LinkedList;import java.util.Queue;class GFG { // Node for the given binary tree static class node { int weight; // stores the weight of node int level; // stores the level of node node left; node right; public node(int w, int l) { this.weight = w; this.level = l; left = right = null; } } // Utility function to insert a node // in a tree rooted at root static node insert(node root, int n_weight, int n_level, Queue<node> q) { node n = new node(n_weight, n_level); // if the tree is empty till now // make node n the root if (root == null) root = n; // If the frontmost node of // queue has no left child // make node n its left child // the frontmost node still // remains in the queue because // its right child isnull yet else if (q.peek().left == null) { q.peek().left = n; } // Make node n the right child of // the frontmost node and remove // the front node from queue else { q.peek().right = n; q.poll(); } // push the node n into queue q.add(n); return root; } // Function to create a complete binary tree static node createTree(ArrayList<Integer> weights, ArrayList<Integer> levels) { // initialise the root node of tree node root = null; // initialise a queue of nodes Queue<node> q = new LinkedList<>(); int n = weights.size(); for (int i = 0; i < n; i++) { /* * keep inserting nodes with weight values * from the weights vector and level * values from the levels vector */ root = insert(root, weights.get(i), levels.get(i), q); } return root; } // Function to print final levels of nodes static void printNodeLevels(node root) { if (root == null) return; Queue<node> q = new LinkedList<>(); q.add(root); while (!q.isEmpty()) { System.out.print(q.peek().level + " "); if (q.peek().left != null) q.add(q.peek().left); if (q.peek().right != null) q.add(q.peek().right); q.poll(); } System.out.println(); } // Function to find the weight of subtree static int findWeight(node root) { // If the root node isnull // then weight of subtree will be 0 if (root == null) return 0; return root.weight + findWeight(root.left) + findWeight(root.right); } // Function to compute new level // of the nodes based on the // difference of weight K static void changeLevels(node root, int k) { if (root == null) return; // Change the level of root node root.level = root.level + k; // Recursively change the level of // left and right subtree changeLevels(root.left, k); changeLevels(root.right, k); } // Function to calculate weight of // the left and the right subtrees and // adjust levels based on their difference static void adjustLevels(node root) { // No adjustment required // when root isnull if (root == null) return; // Find weights of left // and right subtrees int w_left = findWeight(root.left); int w_right = findWeight(root.right); // find the difference between the // weights of left and right subtree int w_diff = w_left - w_right; // Change the levels of nodes // according to weight difference at root changeLevels(root.left, -w_diff); changeLevels(root.right, w_diff); // Recursively adjust the levels // for left and right subtrees adjustLevels(root.left); adjustLevels(root.right); } // Driver code public static void main(String[] args) { // Number of levels int N = 3; // Number of nodes int nodes = (int) Math.pow(2, N) - 1; // Vector to store weights of tree nodes ArrayList<Integer> weights = new ArrayList<>(); for (int i = 1; i <= nodes; i++) { weights.add(i); } // Vector to store levels of every nodes ArrayList<Integer> levels = new ArrayList<>(); for (int i = 0; i < N; i++) { // 2^i nodes are present at ith level for (int j = 0; j < (int) Math.pow(2, i); j++) { // value of level becomes negative // while going down the root levels.add(-1 * i); } } // Create tree with the // given weights and levels node root = createTree(weights, levels); // Adjust the levels adjustLevels(root); // Display the final levels printNodeLevels(root); }}// This code is contributed by sanjeev2552 |
Python3
# Python3 Program to print # updated levels of each # node of a Complete Binary # Tree based on difference # in weights of subtrees import math# Node for the given binary# treeclass node: def __init__(self, w, l): self.weight = w self.level = l self.left = None self.right = None # Utility function to insert # a node in a tree rooted at # rootdef insert(root, n_weight, n_level, q): n = node(n_weight, n_level); # if the tree is empty # till now make node n # the root if (root == None): root = n; # If the frontmost node of # queue has no left child # make node n its left child # the frontmost node still # remains in the queue because # its right child is null yet elif (q[0].left == None): q[0].left = n; # Make node n the right # child of the frontmost # node and remove the # front node from queue else: q[0].right = n; q.pop(0); # push the node n # into queue q.append(n); return root;# Function to create a # complete binary treedef createTree(weights, levels): # initialise the root # node of tree root = None; # initialise a queue # of nodes q = [] n = len(weights) for i in range(n): ''' keep inserting nodes with weight values from the weights vector and level values from the levels vector ''' root = insert(root, weights[i], levels[i], q); return root;# Function to print final# levels of nodesdef printNodeLevels(root): if (root == None): return; q = [] q.append(root); while (len(q) != 0): print(q[0].level, end = ' ') if (q[0].left != None): q.append(q[0].left); if (q[0].right != None): q.append(q[0].right); q.pop(0); print() # Function to find the weight # of subtreedef findWeight(root): # If the root node is # null then weight of # subtree will be 0 if (root == None): return 0; return (root.weight + findWeight(root.left) + findWeight(root.right)); # Function to compute new level# of the nodes based on the# difference of weight Kdef changeLevels(root, k): if (root == None): return; # Change the level of # root node root.level = root.level + k; # Recursively change the # level of left and right # subtree changeLevels(root.left, k); changeLevels(root.right, k);# Function to calculate weight # of the left and the right # subtrees and adjust levels # based on their differencedef adjustLevels(root): # No adjustment required # when root is null if (root == None): return; # Find weights of left # and right subtrees w_left = findWeight(root.left); w_right = findWeight(root.right); # find the difference between # the weights of left and # right subtree w_diff = w_left - w_right; # Change the levels of nodes # according to weight difference # at root changeLevels(root.left, -w_diff); changeLevels(root.right, w_diff); # Recursively adjust the levels # for left and right subtrees adjustLevels(root.left); adjustLevels(root.right);# Driver codeif __name__=="__main__": # Number of levels N = 3; # Number of nodes nodes = int(math.pow(2, N)) - 1; weights = [] # Vector to store weights # of tree nodes for i in range(1, nodes + 1): weights.append(i); levels = [] # Vector to store levels # of every nodes for i in range(N): # 2^i nodes are present # at ith level for j in range(pow(2, i)): # value of level becomes # negative while going # down the root levels.append(-1 * i); # Create tree with the # given weights and levels root = createTree(weights, levels); # Adjust the levels adjustLevels(root); # Display the final levels printNodeLevels(root); # This code is contributed by Rutvik_56 |
C#
// C# Program to print updated levels// of each node of a Complete Binary Tree// based on difference in weights of subtreesusing System;using System.Collections.Generic;class GFG { // Node for the given binary tree class node { public int weight, level; public node left, right; public node(int w, int l) { this.weight = w; this.level = l; left = right = null; } } // Utility function to insert a node // in a tree rooted at root static node insert(node root, int n_weight, int n_level, List<node> q) { node n = new node(n_weight, n_level); // if the tree is empty till now // make node n the root if (root == null) root = n; // If the frontmost node of // queue has no left child // make node n its left child // the frontmost node still // remains in the queue because // its right child isnull yet else if (q[0].left == null) { q[0].left = n; } // Make node n the right child of // the frontmost node and remove // the front node from queue else { q[0].right = n; q.RemoveAt(0); } // push the node n into queue q.Add(n); return root; } // Function to create a complete binary tree static node createTree(List<int> weights, List<int> levels) { // initialise the root node of tree node root = null; // initialise a queue of nodes List<node> q = new List<node>(); int n = weights.Count; for (int i = 0; i < n; i++) { /* * keep inserting nodes with weight values * from the weights vector and level * values from the levels vector */ root = insert(root, weights[i], levels[i], q); } return root; } // Function to print final levels of nodes static void printNodeLevels(node root) { if (root == null) return; List<node> q = new List<node>(); q.Add(root); while (q.Count > 0) { Console.Write(q[0].level + " "); if (q[0].left != null) q.Add(q[0].left); if (q[0].right != null) q.Add(q[0].right); q.RemoveAt(0); } Console.WriteLine(); } // Function to find the weight of subtree static int findWeight(node root) { // If the root node isnull // then weight of subtree will be 0 if (root == null) return 0; return root.weight + findWeight(root.left) + findWeight(root.right); } // Function to compute new level // of the nodes based on the // difference of weight K static void changeLevels(node root, int k) { if (root == null) return; // Change the level of root node root.level = root.level + k; // Recursively change the level of // left and right subtree changeLevels(root.left, k); changeLevels(root.right, k); } // Function to calculate weight of // the left and the right subtrees and // adjust levels based on their difference static void adjustLevels(node root) { // No adjustment required // when root isnull if (root == null) return; // Find weights of left // and right subtrees int w_left = findWeight(root.left); int w_right = findWeight(root.right); // find the difference between the // weights of left and right subtree int w_diff = w_left - w_right; // Change the levels of nodes // according to weight difference at root changeLevels(root.left, -w_diff); changeLevels(root.right, w_diff); // Recursively adjust the levels // for left and right subtrees adjustLevels(root.left); adjustLevels(root.right); } static void Main() { // Number of levels int N = 3; // Number of nodes int nodes = (int) Math.Pow(2, N) - 1; // Vector to store weights of tree nodes List<int> weights = new List<int>(); for (int i = 1; i <= nodes; i++) { weights.Add(i); } // Vector to store levels of every nodes List<int> levels = new List<int>(); for (int i = 0; i < N; i++) { // 2^i nodes are present at ith level for (int j = 0; j < (int) Math.Pow(2, i); j++) { // value of level becomes negative // while going down the root levels.Add(-1 * i); } } // Create tree with the // given weights and levels node root = createTree(weights, levels); // Adjust the levels adjustLevels(root); // Display the final levels printNodeLevels(root); }}// This code is contributed by suresh07. |
Javascript
<script> // JavaScript Program to print updated levels // of each node of a Complete Binary Tree // based on difference in weights of subtrees // Node for the given binary tree class node { constructor(w, l) { this.left = null; this.right = null; this.weight = w; this.level = l; } } // Utility function to insert a node // in a tree rooted at root function insert(root, n_weight, n_level, q) { let n = new node(n_weight, n_level); // if the tree is empty till now // make node n the root if (root == null) root = n; // If the frontmost node of // queue has no left child // make node n its left child // the frontmost node still // remains in the queue because // its right child isnull yet else if (q[0].left == null) { q[0].left = n; } // Make node n the right child of // the frontmost node and remove // the front node from queue else { q[0].right = n; q.shift(); } // push the node n into queue q.push(n); return root; } // Function to create a complete binary tree function createTree(weights, levels) { // initialise the root node of tree let root = null; // initialise a queue of nodes let q = []; let n = weights.length; for (let i = 0; i < n; i++) { /* * keep inserting nodes with weight values * from the weights vector and level * values from the levels vector */ root = insert(root, weights[i], levels[i], q); } return root; } // Function to print final levels of nodes function printNodeLevels(root) { if (root == null) return; let q = []; q.push(root); while (q.length > 0) { document.write(q[0].level + " "); if (q[0].left != null) q.push(q[0].left); if (q[0].right != null) q.push(q[0].right); q.shift(); } document.write("</br>"); } // Function to find the weight of subtree function findWeight(root) { // If the root node isnull // then weight of subtree will be 0 if (root == null) return 0; return root.weight + findWeight(root.left) + findWeight(root.right); } // Function to compute new level // of the nodes based on the // difference of weight K function changeLevels(root, k) { if (root == null) return; // Change the level of root node root.level = root.level + k; // Recursively change the level of // left and right subtree changeLevels(root.left, k); changeLevels(root.right, k); } // Function to calculate weight of // the left and the right subtrees and // adjust levels based on their difference function adjustLevels(root) { // No adjustment required // when root isnull if (root == null) return; // Find weights of left // and right subtrees let w_left = findWeight(root.left); let w_right = findWeight(root.right); // find the difference between the // weights of left and right subtree let w_diff = w_left - w_right; // Change the levels of nodes // according to weight difference at root changeLevels(root.left, -w_diff); changeLevels(root.right, w_diff); // Recursively adjust the levels // for left and right subtrees adjustLevels(root.left); adjustLevels(root.right); } // Number of levels let N = 3; // Number of nodes let nodes = Math.pow(2, N) - 1; // Vector to store weights of tree nodes let weights = []; for (let i = 1; i <= nodes; i++) { weights.push(i); } // Vector to store levels of every nodes let levels = []; for (let i = 0; i < N; i++) { // 2^i nodes are present at ith level for (let j = 0; j < Math.pow(2, i); j++) { // value of level becomes negative // while going down the root levels.push(-1 * i); } } // Create tree with the // given weights and levels let root = createTree(weights, levels); // Adjust the levels adjustLevels(root); // Display the final levels printNodeLevels(root); </script> |
Output:
0 4 -6 4 2 -6 -8
Time Complexity: O(N), Where N is the total number of nodes in the tree.
Auxiliary Space: O(N)
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