判断两颗树是否相同

/** * Definition for binary tree * 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)            return true;        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);    }}