Print a Binary Tree in Vertical Order | Set 2 (Hashmap based Method) | GeeksforGeeks

Print a Binary Tree in Vertical Order | Set 2 (Hashmap based Method) | GeeksforGeeks
Given a binary tree, print it vertically.

// Utility function to store vertical order in map 'm'

// 'hd' is horigontal distance of current node from root.

// 'hd' is initally passed as 0

void getVerticalOrder(Node* root, int hd, map<int, vector<int>> &m)

{

    // Base case

    if (root == NULL)

        return;

    // Store current node in map 'm'

    m[hd].push_back(root->key);

    // Store nodes in left subtree

    getVerticalOrder(root->left, hd-1, m);

    // Store nodes in right subtree

    getVerticalOrder(root->right, hd+1, m);

}

// The main function to print vertical oder of a binary tree

// with given root

void printVerticalOrder(Node* root)

{

    // Create a map and store vertical oder in map using

    // function getVerticalOrder()

    map < int,vector<int> > m;

    int hd = 0;

    getVerticalOrder(root, hd,m);

    // Traverse the map and print nodes at every horigontal

    // distance (hd)

    map< int,vector<int> > :: iterator it;

    for (it=m.begin(); it!=m.end(); it++)

    {

        for (int i=0; i<it->second.size(); ++i)

            cout << it->second[i] << " ";

        cout << endl;

    }

}

Read full article from Print a Binary Tree in Vertical Order | Set 2 (Hashmap based Method) | GeeksforGeeks