572. Subtree of Another Tree ⭐
Medium
Given the roots of two binary trees
root and subRoot, return true if there is a subtree of root with the same structure and node values of subRoot and false otherwise.A subtree of a binary tree
tree is a tree that consists of a node in tree and all of this node's descendants. The tree tree could also be considered as a subtree of itself.Example 1:
Input: root = [3,4,5,1,2], subRoot = [4,1,2]
Output:
true
Example 2:
Input: root = [3,4,5,1,2,null,null,null,null,0], subRoot = [4,1,2]
Output:
false
Constraints:
- The number of nodes in the
roottree is in the range[1, 2000]. - The number of nodes in the
subRoottree is in the range[1, 1000]. -104 <= root.val <= 104-104 <= subRoot.val <= 104
/**
* Definition for a binary tree node.
* type TreeNode struct {
* Val int
* Left *TreeNode
* Right *TreeNode
* }
*/
func isSubtree(root *TreeNode, subRoot *TreeNode) bool {
if root == nil {
return false
}
if isSame(root, subRoot) { return true }
return isSubtree(root.Left, subRoot) || isSubtree(root.Right, subRoot)
}
func isSame(root *TreeNode, subRoot *TreeNode) bool {
if root == nil && subRoot == nil { return true }
if root == nil || subRoot == nil { return false }
if root.Val != subRoot.Val { return false }
return isSame(root.Left, subRoot.Left) && isSame(root.Right, subRoot.Right)
}