首页 > 代码库 > 106. Construct Binary Tree from Inorder and Postorder Traversal

106. Construct Binary Tree from Inorder and Postorder Traversal

Given inorder and postorder traversal of a tree, construct the binary tree.

Note:
You may assume that duplicates do not exist in the tree.

 

Hide Company Tags
 Microsoft
Show Tags
Hide Similar Problems
 
/** * Definition for a binary tree node. * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */public class Solution {    public TreeNode buildTree(int[] inorder, int[] postorder) {        return buildSubTree(0, postorder.length -1, postorder, inorder, 0, postorder.length-1);    }    public TreeNode buildSubTree(int postLeft, int postRight, int[] postorder, int[] inorder, int inLeft, int inRight){        if(postRight < postLeft || inLeft > inRight) return null;        int mid = inLeft;        TreeNode root = new TreeNode(postorder[postRight]);        while(mid <= inRight){            if(postorder[postRight] == inorder[mid]){                root.left = buildSubTree(postLeft, postRight+mid-inRight -1 , postorder, inorder, inLeft, mid-1);                root.right = buildSubTree(postRight+mid-inRight, postRight -1, postorder, inorder, mid+1, inRight);            }            mid++;        }        return root;    }}

 

106. Construct Binary Tree from Inorder and Postorder Traversal