Same Tree

判断两棵树是不是相同的，结构和数值上都相同

/** * 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 p.val == q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);        }        else if(p == null && q == null){            return true;        }else{            return false;        }    }        }