题解 | #重建二叉树#

/* function TreeNode(x) {
    this.val = x;
    this.left = null;
    this.right = null;
} */
    function reConstructBinaryTree(pre, vin)
{
    if (pre.length === 0 ) {
        return null
    }
    let root = pre[0]
    let rootNode = new TreeNode(root)
    let idx = vin.findIndex((item) => item === root)
    rootNode.left = reConstructBinaryTree(pre.slice(1, idx + 1), vin.slice(0, idx))
    rootNode.right = reConstructBinaryTree(pre.splice(idx + 1), vin.slice(idx + 1))
    return rootNode

}