Subtree of Another Tree

<-E 572> Subtree of Another Tree

/**
 * 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* s, TreeNode* t) {
        if (!s && !t) 
            return true;
        if (!s || !t) 
            return false;
        
        return (s->val == t->val) && isSameTree(s->left, t->left) && isSameTree(s->right, t->right);
        
    }
    bool isSubtree(TreeNode* s, TreeNode* t) {
        if (!s && !t) 
            return true;
        
        if (!s || !t) 
            return false;
        return isSameTree(s,t) || isSubtree(s->left, t) || isSubtree(s->right, t);
    }
};