Given the root of a binary tree, the depth of each node is the shortest distance to the root.
Return the smallest subtree such that it contains all the deepest nodes in the original tree.
A node is called the deepest if it has the largest depth possible among any node in the entire tree.
The subtree of a node is a tree consisting of that node, plus the set of all descendants of that node.
Example 1:
Input: root = [3,5,1,6,2,0,8,null,null,7,4]
Output: [2,7,4]
Explanation: We return the node with value 2, colored in yellow in the diagram.
The nodes coloured in blue are the deepest nodes of the tree.
Notice that nodes 5, 3 and 2 contain the deepest nodes in the tree but node 2 is the smallest subtree among them, so we return it.
Example 2:
Input: root = [1]
Output: [1]
Explanation: The root is the deepest node in the tree.
Example 3:
Input: root = [0,1,3,null,2]
Output: [2]
Explanation: The deepest node in the tree is 2, the valid subtrees are the subtrees of nodes 2, 1 and 0 but the subtree of node 2 is the smallest.
Constraints:
The number of nodes in the tree will be in the range [1, 500].
/** * Definition for a binary tree node. * type TreeNode struct { * Val int * Left *TreeNode * Right *TreeNode * } */typepairstruct{first*TreeNodesecondint}funcsubtreeWithAllDeepest(root*TreeNode)*TreeNode{vardfsfunc(root*TreeNode)pairdfs=func(root*TreeNode)pair{ifroot==nil{returnpair{nil,0}}l,r:=dfs(root.Left),dfs(root.Right)d1,d2:=l.second,r.secondifd1>d2{returnpair{l.first,d1+1}}ifd1<d2{returnpair{r.first,d2+1}}returnpair{root,d1+1}}returndfs(root).first}