SameTree.cs

// Source : https://leetcode.com/problems/same-tree/ 
// Author : codeyu 
// Date : Thursday, March 9, 2017 11:50:32 PM 

/**********************************************************************************
*
* 
* 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.
* 
*
**********************************************************************************/

using System;
using System.Collections.Generic;
using Algorithms.Utils;
namespace Algorithms
{
 /**
 * Definition for a binary tree node.
 * public class TreeNode {
 * public int val;
 * public TreeNode left;
 * public TreeNode right;
 * public TreeNode(int x) { val = x; }
 * }
 */
 public class Solution100
 {
 public static bool IsSameTree(TreeNode p, TreeNode q)
 {
 if(p == null && q == null) return true; //顺序很重要，先判断
 if(p == null || q == null) return false;
 if(p.Val != q.Val) return false;
 return IsSameTree(p.Left, q.Left) && IsSameTree(p.Right, q.Right);
 }
 }
}