099. Same Tree/solution.h

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
 
 struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 };
 
class Solution {
public:
    bool isSameTree(TreeNode *p, TreeNode *q) {
        if (p && q) return (p->val == q->val) && isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
        else if (!p && !q) return true;
        else return false;
    }
};