题目描述 输入某二叉树的前序遍历和中序遍历的结果，请重建出该二叉树。假设输入的前序遍历和中序遍历的结果中都不含重复的数字。例如输入前序遍历序列{1,2,4,7,3,5,6,8}和中序遍历序列{4,7,2,1,5,3,8,6}，则重建二叉树并返回。
public class Solution { public TreeNode reConstructBinaryTree(int [] PRe,int [] in) { return BuildTree(pre, in, 0, pre.length-1, 0, in.length-1); } public TreeNode BuildTree(int [] pre, int [] in, int preSt, int preEn, int inSt, int inEn){ if(preSt > preEn || inSt > inEn){ return null; } TreeNode treeNode = new TreeNode(pre[preSt]); for (int i=inSt; i<=inEn; i++){ if(pre[preSt] == in[i]){ treeNode.left = BuildTree(pre, in, preSt+1, preEn, inSt, i-1); treeNode.right = BuildTree(pre, in, preSt+1+i-inSt,preEn,i+1, inEn); } } return treeNode; }}新闻热点
疑难解答
