Given a Binary Tree. The task is to print the circular reverse clockwise spiral order traversal of the given binary tree.
Reverse Clockwise Traversal means to traverse the tree in clockwise direction spirally starting from the bottom instead of top root node.
Input : 1 / \ 2 3 / \ \ 4 5 6 / / \ 7 8 9 Output : 9 8 7 1 6 5 4 2 3 Input : 20 / \ 8 22 / \ / \ 5 3 4 25 / \ 10 14 Output : 14 10 20 25 4 3 5 8 22
Approach: The idea is to use two variables i initialized to 1 and j initialized to the height of tree and run a while loop which wont break until i becomes greater than j.
- Use another variable flag and initialize it to 0. Now in the while loop, check a condition that if flag is equal to 0 then traverse the tree from right to left and mark flag as 1 so that next time we traverse the tree from left to right, this is done to maintain the spiral clockwise order of traversal.
- Also when we will traverse the level from top we will mark flag as 0 so that next time we traverse the tree from right to left and then increment the value of i so that next time we visit the level just below the current level.
- Repeat the whole process until the binary tree is completely traversed.
<liThen decrement the value of j so that next time the level just above the current level is visited.
Below is the implementation of the above approach:
7 6 5 4 1 3 2
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