Given two non-empty binary trees s and t, check whether tree t has exactly the same structure and node values with a subtree of s. A subtree of s is a tree consists of a node in s and all of this node's descendants. The tree s could also be considered as a subtree of itself.
Example 1:
Given tree s:
3
/ \
4 5
/ \
1 2
Given tree t:
4 / \ 1 2
Return true, because t has the same structure and node values with a subtree of s.
Example 2:
Given tree s:
3
/ \
4 5
/ \
1 2
/
0
Given tree t:
4 / \ 1 2
Return false.
Related Topics:
Tree
Similar Questions:
// OJ: https://leetcode.com/problems/shortest-unsorted-continuous-subarray
// Author: github.com/lzl124631x
// Time: O(ST) where S and T are the node count of s and t.
// Space: O(H) where H is the height of s.
class Solution {
private:
bool isSameTree(TreeNode* s, TreeNode* t) {
return (!s && !t) || (s && t && s->val == t->val && isSameTree(s->left, t->left) && isSameTree(s->right, t->right));
}
public:
bool isSubtree(TreeNode* s, TreeNode* t) {
return isSameTree(s, t) || (s && (isSubtree(s->left, t) || isSubtree(s->right, t)));
}
};