34 lines
1.1 KiB
Markdown
34 lines
1.1 KiB
Markdown
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Given a binary tree `root`, a node _X_ in the tree is named **good** if in the path from root to _X_ there are no nodes with a value _greater than_ X.
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Return the number of **good** nodes in the binary tree.
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**Example 1:**
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****
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Input: root = [3,1,4,3,null,1,5]
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Output: 4
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Explanation: Nodes in blue are good.
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Root Node (3) is always a good node.
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Node 4 -> (3,4) is the maximum value in the path starting from the root.
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Node 5 -> (3,4,5) is the maximum value in the path
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Node 3 -> (3,1,3) is the maximum value in the path.
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**Example 2:**
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****
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Input: root = [3,3,null,4,2]
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Output: 3
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Explanation: Node 2 -> (3, 3, 2) is not good, because "3" is higher than it.
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**Example 3:**
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Input: root = [1]
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Output: 1
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Explanation: Root is considered as good.
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**Constraints:**
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* The number of nodes in the binary tree is in the range `[1, 10^5]`.
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* Each node's value is between `[-10^4, 10^4]`.
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