判断二叉树是否相等

/**
* 判断两个二叉树是否相等
* @param t1
* @param t2
* @return
*/
public boolean isSameTree(TreeNode t1, TreeNode t2){
if (t1 == null && t2 == null){
return true;
}
if (t1 == null || t2 == null){
return false;
}
if (t1.val != t2.val){
return false;
}
return isSameTree(t1.left, t2.left) && isSameTree(t1.right, t2.right);
}