Given a Binary Tree, the task is to flatten it in order of ZigZag traversal of the tree. In the flattened binary tree, the left node of all the nodes must be NULL.
Input: 1 / \ 5 2 / \ / \ 6 4 9 3 Output: 1 2 5 6 4 9 3 Input: 1 \ 2 \ 3 \ 4 \ 5 Output: 1 2 3 4 5
Approach: We will solve this problem by simulating the ZigZag traversal of Binary Tree.
- Create two stacks, “c_lev” and “n_lev” and to store the nodes of current and next level Binary tree.
- Create a variable “prev” and initialise it by parent node.
- Push right and left children of parent in the c_lev stack.
- Apply ZigZag traversal. Lets say “curr” is top most element in “c_lev”. Then,
- If ‘curr’ is NULL, continue.
- Else push curr->left and curr->right on the stack “n_lev” in appropriate order. If we are performing left to right traversal then curr->left is pushed first else curr->right is pushed first.
- Set prev = curr.
Below is the implementation of the above approach:
1 2 5 6 4 9 3
Time Complexity: O(N)
Space Complexity: O(N) where N is the size of Binary Tree.
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- Zig-Zag traversal of a Binary Tree using Recursion
- Vertical Zig-Zag traversal of a Tree
- Flatten Binary Tree in order of Level Order Traversal
- Flatten binary tree in order of post-order traversal
- Level order traversal of Binary Tree using Morris Traversal
- Flatten a binary tree into linked list
- Flatten BST to sorted list | Decreasing order
- Flatten BST to sorted list | Increasing order
- Check if a binary tree is subtree of another binary tree using preorder traversal : Iterative
- Build Binary Tree from BST such that it's level order traversal prints sorted data
- Calculate height of Binary Tree using Inorder and Level Order Traversal
- Create a binary tree from post order traversal and leaf node array
- Check if the level order traversal of a Binary Tree results in a palindrome
- Middle To Up-Down Order traversal of a Binary Tree
- Boundary Level order traversal of a Binary Tree
- Double Order Traversal of a Binary Tree
- Specific Level Order Traversal of Binary Tree
- Deletion of a given node K in a Binary Tree using Level Order Traversal
- Find the kth node in vertical order traversal of a Binary Tree
- Print Binary Tree levels in sorted order | Set 3 (Tree given as array)
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