LC 872. Leaf-Similar Trees

1.题目

872. Leaf-Similar Trees

Easy

25914

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 root1and root2 are leaf-similar.

Note:

扫描二维码关注公众号，回复： 4464491 查看本文章

• Both of the given trees will have between 1 and 100 nodes.

2.解题思路

DFS搜索所有叶子结点，用一个vector保存，直接比较两个vector是否相等

3.代码

/**
 * 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> leaf1, leaf2;
        getleaf(root1, leaf1);
        getleaf(root2, leaf2);
        return leaf1 == leaf2;//直接比较两个容器是否相等
    }

    void getleaf(TreeNode* root, vector<int>& leaf)//DFS遍历
    {
        if(root == NULL)    return;
        if(root->left == NULL && root->right == NULL)
            leaf.push_back(root->val);    
        getleaf(root->left, leaf);
        getleaf(root->right, leaf);
    }
};