重建二叉树

class TreeNode:
    def __init__(self, x):
        self.val = x        
        self.left = None        
        self.right = None
class Solution:    
    # 返回构造的TreeNode根节点    
    def reConstructBinaryTree(self, pre, tin):        
        # write code here        
        if len(pre) == 0:            
            return None        
        if len(pre) == 1:            
            return TreeNode(pre[0])        
        else:            
            res = TreeNode(pre[0])   
            # 中左         
            res.left = self.reConstructBinaryTree(pre[1: tin.index(pre[0]) + 1], tin[: tin.index(pre[0])])
             # 中右           
            res.right = self.reConstructBinaryTree(pre[tin.index(pre[0]) + 1: ], tin[tin.index(pre[0]) + 1: ])        
        return res

package main

import "fmt"

type binaryTreeNode struct {
    Value int
    Left  *binaryTreeNode
    Right *binaryTreeNode
}

func (root *binaryTreeNode) preorderTraversal() {
    if root == nil {
        return
    }
    fmt.Printf("%d\t", root.Value)
    if root.Left != nil {
        root.Left.preorderTraversal()
    }
    if root.Right != nil {
        root.Right.preorderTraversal()
    }
}

func (root *binaryTreeNode) inorderTraversal() {
    if root == nil {
        return
    }
    if root.Left != nil {
        root.Left.inorderTraversal()
    }
    fmt.Printf("%d\t", root.Value)
    if root.Right != nil {
        root.Right.inorderTraversal()
    }
}

func construct(preorderSlice []int, inorderSlice []int) (root *binaryTreeNode) {
    if len(preorderSlice) == 0 || len(inorderSlice) == 0 {
        return
    }
    v, i := preorderSlice[0], 0
    for ; inorderSlice[i] != v; i++ {
    }
    root = &binaryTreeNode{Value:v}
    root.Left = construct(preorderSlice[1:i+1], inorderSlice[:i])
    root.Right = construct(preorderSlice[i+1:], inorderSlice[i+1:])
    return
}

func main() {
    preorderSlice := []int{1, 2, 4, 7, 3, 5, 6, 8}
    inorderSlice := []int{4, 7, 2, 1, 5, 3, 8, 6}
    root := construct(preorderSlice, inorderSlice)
    root.preorderTraversal()
    fmt.Println()
    root.inorderTraversal()
}