[Leetcode] Construct Binary Tree from Inorder and Postorder Traversal (Java)

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

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

给定中序遍历与后序遍历结果，构造二叉树

递归

public class Solution {
    public TreeNode buildTree(int[] inorder, int[] postorder) {
        
		if(inorder.length<1)
			return null;
			
		TreeNode root = new TreeNode(postorder[postorder.length-1]);
		int index = 0;
		for(index=0;index<inorder.length;index++){
			if(inorder[index]==postorder[postorder.length-1])
				break;
		}
		
		if(index>0){
			int[] preP = new int[index];
			int[] preI = new int[index];
			for(int i=0;i<index;i++){
				preP[i]=postorder[i];
				preI[i]=inorder[i];
			}
			root.left = buildTree(preI,preP);
		}
		
		if(postorder.length-index-1>0){
			int[] postP = new int[postorder.length-index-1];
			int[] postI = new int[inorder.length-index-1];
			for(int i=index+1;i<postorder.length;i++){
				postP[i-index-1]=postorder[i-1];
				postI[i-index-1]=inorder[i];
			}
			root.right = buildTree(postI, postP);
		}
		
		return root;    
    }
}