Given a Binary Tree consisting of N nodes, the task is to first compress the tree diagonally to get a list of integers and then, again compress the list to get a single integer using the following operations:
- When a tree is compressed diagonally, its value in binary representation gets compressed.
- Consider each bit position of each node value present in a diagonal. If a position has S set bits and NS non-set bits, then set the bit for that position only if S is greater than NS. Otherwise, unset the bit for that position.
- Compress each diagonal to convert the tree into a list. Then, compress each array element into a single integer by using the same process.
Example: If 7, 6, 3 and 4 gets compressed, then their binary representations, i.e. (111)2, (110)2, (011)2 and (100)2 gets compressed. For the 0th position, S ? NS and for the 1st and 2nd positions, S > NS.
Therefore, the number becomes (110)2 = 6.
Examples:
Input: 6
/ \
5 3
/ \ / \
3 5 3 4
Output: 3
Explanation:Diagonal 1: Compress( 6, 3, 4 ) = 6
Diagonal 2: Compress( 5, 5, 3 ) = 5
Diagonal 3: Compress( 3 ) = 3
Finally, compress the list (6, 5, 3) to get 7.Input: 10
/ \
5 2
/ \
6 8
Output: 2
Approach: The idea is to use a Hashmap to store all the nodes which belong to a particular diagonal of the tree. Follow the steps below to solve the problem:
- For the diagonal traversal of the tree, keep track of the horizontal distance from the root node for each node.
- Use a Hashmap to store the elements belonging to the same diagonal.
- After the traversal, count the number of set bits for each position for each diagonal of the tree and set the bit for the positions where the number of set bits exceeds the number of unset bits.
- Store the compressed value of each diagonal in an array.
- After obtaining the array, apply the same steps for compression to obtain the required integer.
Below is the implementation of the above approach:
C++
#include <bits/stdc++.h> using namespace std; struct TreeNode{ int val; TreeNode *left,*right; TreeNode( int v){ val = v; left = NULL; right = NULL; } }; // Function to compress the elements // in an array into an integer int findCompressValue(vector< int > arr){ int ans = 0; int getBit = 1; // Check for each bit position for ( int i = 0; i < 32; i++){ int S = 0; int NS = 0; for ( int j:arr){ // Update the count of // set and non-set bits if (getBit & j) S += 1; else NS += 1; } // If number of set bits exceeds // the number of non-set bits, // then add set bits value to ans if (S > NS) ans += pow (2,i); getBit <<= 1; } return ans; } // Perform Inorder Traversal // on the Binary Tree void diagonalOrder(TreeNode *root, int d,map< int ,vector< int > > &mp){ if (!root) return ; // Store all nodes of the same // line together as a vector mp[d].push_back(root->val); // Increase the vertical // distance of left child diagonalOrder(root->left, d + 1, mp); // Vertical distance remains // same for right child diagonalOrder(root->right, d, mp); } // Function to compress a given // Binary Tree into an integer int findInteger(TreeNode *root){ // Declare a map map< int ,vector< int > > mp; diagonalOrder(root, 0, mp); //Store all the compressed values of //diagonal elements in an array vector< int > arr; for ( auto i:mp) arr.push_back(findCompressValue(i.second)); // Compress the array into an integer return findCompressValue(arr); } // Driver Code // Given Input int main() { TreeNode *root = new TreeNode(6); root->left = new TreeNode(5); root->right = new TreeNode(3); root->left->left = new TreeNode(3); root->left->right = new TreeNode(5); root->right->left = new TreeNode(3); root->right->right = new TreeNode(4); // Function Call cout << findInteger(root); return 0; } // This code is contributed by mohit kumar 29. |
Java
import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.TreeMap; class TreeNode { public int val; public TreeNode left, right; TreeNode( int v) { val = v; left = null ; right = null ; } } class GfG { // Function to compress the elements in an array into an integer static int findCompressValue(List<Integer> arr) { int ans = 0 ; int getBit = 1 ; // Check for each bit position for ( int i = 0 ; i < 32 ; i++) { int S = 0 ; int NS = 0 ; for ( int j = 0 ; j < arr.size(); j++) { // Update the count of set and non-set bits if ((getBit & arr.get(j)) != 0 ) { S += 1 ; } else { NS += 1 ; } } // If number of set bits exceeds the number of non-set bits, // then add set bits value to ans if (S > NS) { ans += Math.pow( 2 , i); } getBit <<= 1 ; } return ans; } // Perform Inorder Traversal on the Binary Tree void diagonalOrder(TreeNode root, int d, Map<Integer, List<Integer>> mp) { if (root == null ) { return ; } // Store all nodes of the same line together as a vector mp.computeIfAbsent(d, k -> new ArrayList<>()).add(root.val); // Increase the vertical distance of left child diagonalOrder(root.left, d + 1 , mp); // Vertical distance remains same for right child diagonalOrder(root.right, d, mp); } // Function to compress a given Binary Tree into an integer int findInteger(TreeNode root) { // Declare a map Map<Integer, List<Integer>> mp = new TreeMap<>(); diagonalOrder(root, 0 , mp); // Store all the compressed values of diagonal elements in an array List<Integer> arr = new ArrayList<>(); for (Map.Entry<Integer, List<Integer>> entry : mp.entrySet()) { arr.add(findCompressValue(entry.getValue())); } // Compress the array into an integer return findCompressValue(arr); } // Driver code public static void main(String[] args) { // Given input TreeNode root = new TreeNode( 6 ); root.left = new TreeNode( 5 ); root.right = new TreeNode( 3 ); root.left.left = new TreeNode( 3 ); root.left.right = new TreeNode( 5 ); root.right.left = new TreeNode( 3 ); root.right.right = new TreeNode( 4 ); // Function call System.out.println( new GfG().findInteger(root)); } } // This code is contributed by poojaagarwal2 |
Python3
# Python program for the above approach class TreeNode: def __init__( self , val = '', left = None , right = None ): self .val = val self .left = left self .right = right # Function to compress the elements # in an array into an integer def findCompressValue(arr): ans = 0 getBit = 1 # Check for each bit position for i in range ( 32 ): S = 0 NS = 0 for j in arr: # Update the count of # set and non-set bits if getBit & j: S + = 1 else : NS + = 1 # If number of set bits exceeds # the number of non-set bits, # then add set bits value to ans if S > NS: ans + = 2 * * i getBit << = 1 return ans # Function to compress a given # Binary Tree into an integer def findInteger(root): # Declare a map mp = {} # Perform Inorder Traversal # on the Binary Tree def diagonalOrder(root, d, mp): if not root: return # Store all nodes of the same # line together as a vector try : mp[d].append(root.val) except KeyError: mp[d] = [root.val] # Increase the vertical # distance of left child diagonalOrder(root.left, d + 1 , mp) # Vertical distance remains # same for right child diagonalOrder(root.right, d, mp) diagonalOrder(root, 0 , mp) # Store all the compressed values of # diagonal elements in an array arr = [] for i in mp: arr.append(findCompressValue(mp[i])) # Compress the array into an integer return findCompressValue(arr) # Driver Code # Given Input root = TreeNode( 6 ) root.left = TreeNode( 5 ) root.right = TreeNode( 3 ) root.left.left = TreeNode( 3 ) root.left.right = TreeNode( 5 ) root.right.left = TreeNode( 3 ) root.right.right = TreeNode( 4 ) # Function Call print (findInteger(root)) |
C#
// C# code to implement the approach using System; using System.Collections.Generic; // TreeNode class definition class TreeNode { public int val; public TreeNode left, right; // Constructor public TreeNode( int v) { val = v; left = null ; right = null ; } } class GFG { // Function to compress the elements in an array into an // integer static int FindCompressValue(List< int > arr) { int ans = 0; int getBit = 1; // Check for each bit position for ( int i = 0; i < 32; i++) { int S = 0; int NS = 0; for ( int j = 0; j < arr.Count; j++) { // Update the count of set and non-set bits if ((getBit & arr[j]) != 0) { S += 1; } else { NS += 1; } } // If number of set bits exceeds the number of // non-set bits, then add set bits value to ans if (S > NS) { ans += ( int )Math.Pow(2, i); } getBit <<= 1; } return ans; } // Perform Inorder Traversal on the Binary Tree static void DiagonalOrder(TreeNode root, int d, Dictionary< int , List< int > > mp) { if (root == null ) { return ; } // Store all nodes of the same line together as a // vector if (!mp.ContainsKey(d)) { mp[d] = new List< int >(); } mp[d].Add(root.val); // Increase the vertical distance of left child DiagonalOrder(root.left, d + 1, mp); // Vertical distance remains same for right child DiagonalOrder(root.right, d, mp); } // Function to compress a given Binary Tree into an // integer static int FindInteger(TreeNode root) { // Declare a dictionary Dictionary< int , List< int > > mp = new Dictionary< int , List< int > >(); DiagonalOrder(root, 0, mp); // Store all the compressed values of diagonal // elements in an array List< int > arr = new List< int >(); foreach (KeyValuePair< int , List< int > > entry in mp) { arr.Add(FindCompressValue(entry.Value)); } // Compress the array into an integer return FindCompressValue(arr); } // Driver code static void Main( string [] args) { // Given input TreeNode root = new TreeNode(6); root.left = new TreeNode(5); root.right = new TreeNode(3); root.left.left = new TreeNode(3); root.left.right = new TreeNode(5); root.right.left = new TreeNode(3); root.right.right = new TreeNode(4); // Function call Console.WriteLine(FindInteger(root)); } } // This code is contributed by phasing17 |
Javascript
// JavaScript code for the above approach class TreeNode { constructor(val) { this .val = val; this .left = null ; this .right = null ; } } // Function to compress the elements // in an array into an integer function findCompressValue(arr) { let getBit = 1; let ans = 0; // Check for each bit position for (let i = 0; i < 32; i++) { let S = 0; let NS = 0; for (let j of arr) { // Update the count of // set and non-set bits if (getBit & j) { S += 1; } else { NS += 1; } } // If number of set bits exceeds // the number of non-set bits, // then add set bits value to ans if (S > NS) { ans += 2 ** i; } getBit <<= 1; } return ans; } // Perform Inorder Traversal // on the Binary Tree function diagonalOrder(root, d, mp) { if (!root) { return ; } // Store all nodes of the same // line together as a vector if (!mp[d]) { mp[d] = []; } mp[d].push(root.val); // Increase the vertical // distance of left child diagonalOrder(root.left, d + 1, mp); // Vertical distance remains // same for right child diagonalOrder(root.right, d, mp); } // Function to compress a given // Binary Tree into an integer function findInteger(root) { // Declare a map let mp = {}; diagonalOrder(root, 0, mp); // Store all the compressed values of // diagonal elements in an array let arr = []; for (let [key, value] of Object.entries(mp)) { arr.push(findCompressValue(value)); } // Compress the array into an integer return findCompressValue(arr); } // Given Input let root = new TreeNode(6); root.left = new TreeNode(5); root.right = new TreeNode(3); root.left.left = new TreeNode(3); root.left.right = new TreeNode(5); root.right.left = new TreeNode(3); root.right.right = new TreeNode(4); // Function Call console.log(findInteger(root)); // This code is contributed by Potta Lokesh |
7
Time Complexity: O(N)
Auxiliary Space: O(N)
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