import java.util.*; /**
-
Definition for binary tree
-
public class TreeNode {
-
int val;
-
TreeNode left;
-
TreeNode right;
-
TreeNode(int x) { val = x; }
-
} */ //依据题解1写的 public class Solution { public TreeNode reConstructBinaryTree(int [] pre,int [] vin) { if(pre.length == 0) return null; TreeNode root = new TreeNode(pre[0]);//根节点
int index = -1;//根节点在中序遍历的位置 for(int i = 0;i < vin.length;i++) { if(vin[i] == pre[0]) { index = i; } } int[] pre1 = Arrays.copyOfRange(pre, 1, index+1); int[] pre2 = Arrays.copyOfRange(pre, index+1, pre.length); int[] vin1 = Arrays.copyOfRange(vin, 0, index); int[] vin2 = Arrays.copyOfRange(vin, index+1, vin.length); root.left = reConstructBinaryTree(pre1, vin1); root.right = reConstructBinaryTree(pre2, vin2); return root;
} }