题解 | #重建二叉树#

/*
 * function TreeNode(x) {
 *   this.val = x;
 *   this.left = null;
 *   this.right = null;
 * }
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param preOrder int整型一维数组 
 * @param vinOrder int整型一维数组 
 * @return TreeNode类
 */
function reConstructBinaryTree( preOrder ,  vinOrder ) {
    if(preOrder.length==0||vinOrder.length==0)
      return null
    let root =preOrder[0]
    let index = vinOrder.indexOf(root)
    let tree = new TreeNode(root)
    tree.left = reConstructBinaryTree(preOrder.slice(1,index+1),vinOrder.slice(0,index))
    tree.right = reConstructBinaryTree(preOrder.slice(index+1), vinOrder.slice(index+1))
    return tree
}
module.exports = {
    reConstructBinaryTree : reConstructBinaryTree
};