100. Same Tree
Đề Bài
Given the roots of two binary trees p and q, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.
Example 1:
Input: p = [1,2,3], q = [1,2,3] Output: true
Example 2:
Input: p = [1,2], q = [1,null,2] Output: false
Example 3:
Input: p = [1,2,1], q = [1,1,2] Output: false
Constraints:
- The number of nodes in both trees is in the range
[0, 100]. -104 <= Node.val <= 104
Thuật Toán & Kỹ Thuật
⏱️ Thời gian
O(n²)
💾 Không gian
O(1)
Lời Giải
C++
0100-same-tree.cpp
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
bool isSameTree(TreeNode* p, TreeNode* q) {
if (!p and !q) {
return true;
}
if (p and !q) {
return false;
}
if (!p and q) {
return false;
}
if (p->val != q->val) {
return false;
}
return isSameTree(p->left, q->left) and isSameTree(p->right, q->right);
}
};
Python
0100-same-tree.py
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, val=0, left=None, right=None):
# self.val = val
# self.left = left
# self.right = right
class Solution:
def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
if p is None and q is None:
return True
if p and q is None:
return False
if q and p is None:
return False
if p.val != q.val:
return False
return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)