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BASA DSA

Count Good Nodes In Binary Tree

MediumTrees

Count nodes whose value is at least every value on the path from the root to that node. The root always qualifies.

Example 1

Argument 1 tree: level-order input; omitted children are null.Argument 1 tree: level-order input; omitted children are null. Vertices: node 0: 3, node 1: 1, node 2: 4, node 3: 3, node 4: 1, node 5: 5. Edges: node 0 (3) — node 1 (1) left child; node 0 (3) — node 2 (4) right child; node 1 (1) — node 3 (3) left child; node 2 (4) — node 4 (1) left child; node 2 (4) — node 5 (5) right child.314315
Argument 1 tree: level-order input; omitted children are null.

Input
root = [3,1,4,3,null,1,5]
Output
4

Explanation

Root 3, the 3 beneath node 1, node 4 and node 5 qualify; both 1 nodes fail.

Example 2

Argument 1 tree: level-order input; omitted children are null.Argument 1 tree: level-order input; omitted children are null. Vertices: node 0: 2, node 1: 2, node 2: 2. Edges: node 0 (2) — node 1 (2) left child; node 0 (2) — node 2 (2) right child.222
Argument 1 tree: level-order input; omitted children are null.

Input
root = [2,2,2]
Output
3

Explanation

Equality qualifies, so all three nodes of value 2 are good.

Example 3

Argument 1 tree: level-order input; omitted children are null.Argument 1 tree: level-order input; omitted children are null. Vertices: node 0: 8. Edges: none.8
Argument 1 tree: level-order input; omitted children are null.

Input
root = [8]
Output
1

Explanation

A root has no greater ancestor and always qualifies.

Constraints

  • 1 <= number of nodes <= 10000
  • Values are -10000..10000

Function contractgoodNodesArguments: tree
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