[LeetCode] Same Tree

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

/**
 * Definition for binary tree
 * 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) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
        if(p == NULL)
        {
         if(q == NULL)
                return true;
                else 
                return false;
        }
        if(q == NULL)
            return false;
        
        return (p -> val == q -> val) && isSameTree(p -> left, q -> left) && isSameTree(q -> right, p -> right);
    }
};