Print Binary Tree in 2 Dimensions in C++

In this problem, we are given a binary tree and we have to print it two dimensional plane.

Binary Tree is a special tree whose every node has at max two child nodes. So, every node is either a leaf node or has one or two child nodes.

Example,

Let’s take an example to understand the topic better −

Output -

      7
   4
5
      1
   3
      8

Now as we have seen in the example, the nodes of the tree are printed in a 2-D output screen horizontally.

Here, we have flipped the tree by 90o.

Let’s see what the new horizontal tree is made up of,

• The tree data structure is stored in a horizontal way which includes

  • The root at the 1st position in horizontal view n lines below the starting line. i.e. root will be at the start of the nth line.

  • The new levels of the tree are in lines n+i and n-i. And at i tab spaces away from the start of the line.

  • And the rightmost leaf node of the tree is printed in the first line. Whereas the leftmost node of the tree is printed at the last line.

Example

Let’s create a program based on this logic −

 Live Demo

#include<bits/stdc++.h>
#include<iostream>
using namespace std;
#define COUNT 10
class Node{
   public:
      int data;
      Node* left, *right;
      Node(int data){
         this->data = data;
         this->left = NULL;
         this->right = NULL;
      }
};
void printTree(Node *root, int space){
   if (root == NULL)
      return;
   space += COUNT;
   printTree(root->right, space);
   for (int i = COUNT; i < space; i++)
      cout<<"\t";
   cout<<root->data<<"\n";
   printTree(root->left, space);
}
int main(){
   Node *root = new Node(43);
   root->left = new Node(25);
   root->right = new Node(67);
   root->left->left = new Node(14);
   root->left->right = new Node(51);
   root->right->left = new Node(26);
   root->right->right = new Node(97);
   root->left->left->left = new Node(81);
   root->left->left->right = new Node(49);
   root->left->right->left = new Node(07);
   root->left->right->right = new Node(31);
   root->right->left->left = new Node(29);
   root->right->left->right = new Node(13);
   root->right->right->left = new Node(59);
   root->right->right->right = new Node(16);
   printTree(root, 0);
   return 0;
}

Output

         16
      97
         59
   67
         13
      26
         29
43
         31
      51
         7
   25
         49
   14
         81