Description

Given the roots of two binary trees p and q, write a function to check if they are the same or not.

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

Example 1:

Input: p = [1,2,3], q = [1,2,3] Output: true

Example 2:

Input: p = [1,2], q = [1,null,2] Output: false

Example 3:

Input: p = [1,2,1], q = [1,1,2] Output: false

Constraints:

  • The number of nodes in both trees is in the range [0, 100].
  • -104 <= Node.val <= 104

Code

/**
 * 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* p, TreeNode* q) {
        if (p == NULL || q == NULL) return (p == q);
        return (p->val == q->val && isSameTree(p->left, q->left) && isSameTree(p->right, q->right));
    }
};

Source