#include <stdbool.h>
#include <stdlib.h>

struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
};

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
bool isSameTree(struct TreeNode* p, struct TreeNode* q) {
    if (p == NULL && q == NULL) {
        return true;
    }
    if (p == NULL || q == NULL) {
        return false;
    }
    return p->val == q->val
        && isSameTree(p->left, q->left)
        && isSameTree(p->right, q->right);
}