Class Solution
java.lang.Object
g1001_1100.s1028_recover_a_tree_from_preorder_traversal.Solution
public class Solution
extends java.lang.Object
1028 - Recover a Tree From Preorder Traversal.
Hard
We run a preorder depth-first search (DFS) on the root
of a binary tree.
At each node in this traversal, we output D
dashes (where D
is the depth of this node), then we output the value of this node. If the depth of a node is D
, the depth of its immediate child is D + 1
. The depth of the root
node is 0
.
If a node has only one child, that child is guaranteed to be the left child.
Given the output traversal
of this traversal, recover the tree and return its root
.
Example 1:
Input: traversal = “1-2–3–4-5–6–7”
Output: [1,2,5,3,4,6,7]
Example 2:
Input: traversal = “1-2–3—4-5–6—7”
Output: [1,2,5,3,null,6,null,4,null,7]
Example 3:
Input: traversal = “1-401–349—90–88”
Output: [1,401,null,349,88,90]
Constraints:
- The number of nodes in the original tree is in the range
[1, 1000]
. 1 <= Node.val <= 109
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Constructor Summary
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Method Summary
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Constructor Details
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Solution
public Solution()
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Method Details
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recoverFromPreorder
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