872. Leaf-Similar Trees

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 and 100 nodes.

struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

class Solution {
private:
    vector<int> vec1;
    vector<int> vec2;
    void postorderTraversal(TreeNode* root, vector<int>& vec){
        if(!root)
            return;
        postorderTraversal(root->left, vec);
        postorderTraversal(root->right,vec);
        if(!root->left && !root->right){
            vec.push_back(root->val);
        }
    }
public:
    bool leafSimilar(TreeNode* root1, TreeNode* root2) {
        postorderTraversal(root1, vec1);
        postorderTraversal(root2, vec2);
        size_t n1 = vec1.size();
        size_t n2 = vec2.size();
        if(n1 == n2){

            for (int i = 0; i < n1; ++i) {
                if(vec1[i] == vec2[i]){
                    continue;
                }
                else
                    return false;
            }
        }
        else{
            return false;
        }
        return true;
    }
};