1. Description

Given two binary trees, 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.

2. Example

Input:
1 1
/ \ / \
2 3 2 3
[1,2,3], [1,2,3]
Output: true

3. Code

public class LeetCode0100 {

    class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;

        TreeNode(int x) {
            val = x;
        }
    }

    public boolean isSameTree(TreeNode p, TreeNode q) {
        if (p == null) {
            if (q == null) {
                return true;
            } else {
                return false;
            }
        }

        if (q == null || p.val != q.val) {
            return false;
        }

        return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
    }
}