// Author: Li Long, [email protected]

// Date: Apr 17, 2014

// Source: http://oj.leetcode.com/problems/same-tree/

// Analysis: http://blog.csdn.net/lilong_dream/article/details/22753227

// 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

* public class TreeNode {

* int val;

* TreeNode left;

* TreeNode right;

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

* }

*/

public class SameTree {

public boolean isSameTree(TreeNode p, TreeNode q) {

if (p == null && q == null) {

return true;

} else if (p == null || q == null) {

return false;

}

return p.val == q.val && isSameTree(p.left, q.left)

&& isSameTree(p.right, q.right);

}

public static void main(String[] args) {

TreeNode n1 = new TreeNode(1);

TreeNode n2 = new TreeNode(1);

n1.left = n2;

TreeNode n3 = new TreeNode(1);

TreeNode n4 = new TreeNode(1);

n3.right = n4;

SameTree slt = new SameTree();

System.out.println(slt.isSameTree(n1, n3));

}

}