题解 | #从中序与后序遍历序列构造二叉树#

package main
import . "nc_tools"
/*
 * type TreeNode struct {
 *   Val int
 *   Left *TreeNode
 *   Right *TreeNode
 * }
 */

/**
 * 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 inorder int整型一维数组 中序遍历序列
 * @param postorder int整型一维数组 后序遍历序列
 * @return TreeNode类
*/
func buildTree( inorder []int ,  postorder []int ) *TreeNode {
    // write code here
	if len(inorder) == 0 || len(postorder)==0{
		return nil
	}
	rootVal := postorder[len(postorder)-1];
	root := &TreeNode{Val: rootVal};
	rootindex := -1;
	for i,val := range inorder{
		if val == root.Val{
			rootindex=i;
			break;
		}
	}
	root.Left=buildTree(inorder [:rootindex], postorder [:rootindex])
	root.Right=buildTree(inorder [rootindex+1:], postorder [rootindex:len(postorder)-1])
	return root
	

}