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) {

        if(p==NULL && q==NULL) return true;

        if(p==NULL || q==NULL) return false;

        if(p->val==q->val)

            return isSameTree(p->left,q->left) && isSameTree(p->right,q->right);

        else

            return false;

    }

};