872. Leaf-Similar Trees*
https://leetcode.com/problems/leaf-similar-trees/
题目描述
Consider all the leaves of a binary tree. From left to right order, the values of those leaves form a leaf value sequence.
For example, in the given tree above, the leaf value sequence is (6, 7, 4, 9, 8)
.
Two binary trees are considered leaf-similar if their leaf value sequence is the same.
Return true if and only if the two given trees with head nodes root1
and root2
are leaf-similar.
Note:
- Both of the given trees will have between
1
and100
nodes.
C++ 实现 1
前序遍历; 将叶子节点 (左右节点均为空) 加入到数组中, 最后进行数组的比较.
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
bool leafSimilar(TreeNode* root1, TreeNode* root2) {
vector<int> v1, v2;
dfs(root1, v1);
dfs(root2, v2);
return v1 == v2;
}
private:
void dfs(TreeNode *root, vector<int> &res) {
if (!root) return;
if (!root->left && !root->right) res.push_back(root->val);
dfs(root->left, res);
dfs(root->right, res);
}
};