Given a binary tree, the task is to print the sum of nodes in the bottom view of the given Binary Tree. The bottom view of a binary tree is the set of nodes visible when the tree is viewed from the bottom.
Input : 1 / \ 2 3 / \ \ 4 5 6 Output : 20 Input : 1 / \ 2 3 \ 4 \ 5 \ 6 Output : 17
Approach: The idea is to use a queue.
- Put tree nodes in a queue for the level order traversal
- Start with the horizontal distance(hd) 0 of the root node, keep on adding left child to queue along with the horizontal distance as hd-1 and right child as hd+1.
- Use a map to store the hd value(as key) and the last node(as pair) having the corresponding hd value.
- Every time, we encounter a new horizontal distance or an existing horizontal distance put the node data for the horizontal distance as key. For the first time it will add to the map, next time it will replace the value. This will make sure that the bottom-most element for that horizontal distance is present in the map.
- Finally, traverse the map and calculate the sum of all the elements.
Below is the implementation of the above approach:
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- Sum of nodes in the left view of the given binary tree
- Print nodes of a Binary Search Tree in Top Level Order and Reversed Bottom Level Order alternately
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- Print nodes in the Top View of Binary Tree | Set 3
- Print nodes in top view of Binary Tree | Set 2
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- Complexity of different operations in Binary tree, Binary Search Tree and AVL tree
- Print Right View of a Binary Tree
- Iterative Method To Print Left View of a Binary Tree
- Right view of Binary Tree using Queue
- Print Left View of a Binary Tree
- Maximum sub-tree sum in a Binary Tree such that the sub-tree is also a BST
- Construct XOR tree by Given leaf nodes of Perfect Binary Tree
- Minimum difference between any two weighted nodes in Sum Tree of the given Tree
- Check if max sum level of Binary tree divides tree into two equal sum halves
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