leetCode练习（100）

题目：Same Tree

难度：easy

问题描述：

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.

解题思路：

判断两个树是否相等。使用递归即可。若root1.val=roo2.val，则判断左右子树书否相等。

具体代码如下：

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p!=null&&q!=null){
			if(p.val!=q.val){
				return false;
			}else{
				return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);
			}
		}else{
			if(p==null&&q==null){
				return true;
			}else{
				return false;
			}
		}
    }
}