Leaf-Similar Trees Problem & Solution
Consider all the leaves of a binary tree, from left to right order, the values of those leaves form a leaf value sequence.
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.
See the leaf-similar trees problem on LeetCode.
C++ Solution
#pragma GCC optimize("Ofast")
#pragma GCC optimization("max-inline-insns-recursive-auto")
static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();
/**
* 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 leafSimilar(TreeNode* root1, TreeNode* root2) {
vector<int> leaves1;
vector<int> leaves2;
dfs(root1, leaves1);
dfs(root2, leaves2);
return leaves1 == leaves2;
}
private:
void dfs(TreeNode* node, vector<int>& leaves) {
if (node == nullptr) {
return;
}
dfs(node->left, leaves);
if (node->left == nullptr && node->right == nullptr) {
leaves.push_back(node->val);
}
dfs(node->right, leaves);
}
};