题目：输入一棵二叉树的根结点，判断该树是不是平衡二叉树。如果某二叉树中任意结点的左右子树的深度相差不超过1，那么它就是一棵平衡二叉树。

int getHeight(Node node){   if(node==null){      return 0;   }   int heigth = 1;   if(node.left!=null){      height = 1+getHeight(node.left);  }   if(node.rigth!=null){      int h = 1+getHeight(node.right);      height = height>h?height:h;   }  return height;}boolean isBalance(Node node){   if(node==null){     return true;   }   int left = getHeight(node.left);   int right = getHeight(node.right);   int diff = left - right;    if(diff > 1 || diff < -1)        return false;   return isBalance(node.left)&&isBalance(node.right);}