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_156.java
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_156.java
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package com.fishercoder.solutions;
import com.fishercoder.common.classes.TreeNode;
/**
* 156. Binary Tree Upside Down
*
* Given a binary tree where all the right nodes are either leaf nodes with a sibling
* (a left node that shares the same parent node) or empty,
* flip it upside down and turn it into a tree where the original right nodes turned into left leaf nodes. Return the new root.
For example:
Given a binary tree {1,2,3,4,5},
1
/ \
2 3
/ \
4 5
return the root of the binary tree [4,5,2,#,#,3,1].
4
/ \
5 2
/ \
3 1
confused what "{1,#,2,3}" means? > read more on how binary tree is serialized on OJ.
*/
public class _156 {
public static class Solution1 {
public TreeNode upsideDownBinaryTree(TreeNode root) {
if (root == null || root.left == null && root.right == null) {
return root;
}
TreeNode newRoot = upsideDownBinaryTree(root.left);
root.left.left = root.right;
root.left.right = root;
root.left = null;
root.right = null;
return newRoot;
}
}
}