110. Balanced Binary Tree.ipynb

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    "Given a binary tree, determine if it is height-balanced.\n",
    "\n",
    "For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1."
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    "class TreeNode(object):\n",
    "    def __init__(self,x):\n",
    "        self.val=x\n",
    "        self.left=None\n",
    "        self.right=None\n",
    "class Solution(object):\n",
    "    def isBalanced(self, root):\n",
    "        \"\"\"\n",
    "        :type root: TreeNode\n",
    "        :rtype: bool\n",
    "        \"\"\"\n",
    "        def visit(root):\n",
    "            if not root:\n",
    "                return 0\n",
    "            left=visit(root.left)\n",
    "            right=visit(root.right)\n",
    "            if left<0 or right<0 or abs(left-right)>1:\n",
    "                return -1\n",
    "            return 1+max(left,right)\n",
    "        return visit(root)!=-1\n",
    "    \n",
    "    "
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