469 · Same Tree - LintCode

# Description

Check if two binary trees are identical. Identical means the two binary trees have the same structure and every identical position has the same value.

# Example

Example 1:

Input:{1,2,2,4},{1,2,2,4}
Output:true
Explanation:
        1                   1
       / \                 / \
      2   2   and         2   2
     /                   /
    4                   4

are identical.

Example 2:

Input:{1,2,3,4},{1,2,3,#,4}
Output:false
Explanation:

        1                  1
       / \                / \
      2   3   and        2   3
     /                        \
    4                          4

are not identical.

# Solution

	/**
	* Definition of TreeNode:
	* public class TreeNode {
	* public int val;
	* public TreeNode left, right;
	* public TreeNode(int val) {
	* this.val = val;
	* this.left = this.right = null;
	* }
	* }
	*/

	public class Solution {
	/**
	* @param a: the root of binary tree a.
	* @param b: the root of binary tree b.
	* @return: true if they are identical, or false.
	*/
	public boolean isIdentical(TreeNode a, TreeNode b) {
	if (a == null && b == null){
	return true;
	}
	if (a != null && b != null){
	return a.val == b.val && isIdentical(a.left, b.left) && isIdentical(a.right, b.right);
	}

	return false;
	}
	}

algorithm dfs tree