Same Tree leetcode java

题目：

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.

题解：

递归判断左右是否相等。

代码如下：

 1     public boolean isSameTree(TreeNode p, TreeNode q) {
 2         if(p==null&&q==null)
 3             return true;
 4         
 5         if(p==null&&q!=null)
 6             return false;
 7         
 8         if(p!=null&&q==null)
 9             return false;
             
         if(p.val!=q.val)
             return false;
         boolean isleftsame = isSameTree(p.left,q.left);
         if(!isleftsame)
             return false;
             
         boolean isrightsame = isSameTree(p.right,q.right);
         if(!isrightsame)
             return false;
         
         return true;
         
     }

对上述代码更简洁的写法是：

     public boolean isSameTree(TreeNode p, TreeNode q) {
         if(p == null&&q == null)
             return true;
         if(p == null||q == null)
             return false;
         return (p.val == q.val) && isSameTree(p.left,q.left) && isSameTree(p.right,q.right);
     }