04 重建二叉树

public class Solution {
    public TreeNode reConstructBinaryTree(int [] pre,int [] in) {
        return reConstructBinaryTree(pre, 0, pre.length - 1, in, 0, in.length - 1);
    }

    public TreeNode reConstructBinaryTree(int[] pre, int startPre, int endPre, int[] in, int startIn, int endIn){
        if(startPre > endPre || startIn > endIn){
            return null;
        }
        TreeNode root = new TreeNode(pre[startPre]);
        for(int i = startIn; i <= endIn; i++){
            if(in[i] == pre[startPre]){
                root.left = reConstructBinaryTree(pre, startPre + 1, startPre + i, in, startIn, i - 1);
                root.right = reConstructBinaryTree(pre, i - startIn + startPre + 1, endPre, in, i + 1, endIn);
            }
        }
        return root;
    }
}

递归