Leetcode-construct Binary Tree from inorder and preorder travesal

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

Note:
Assume that duplicates does not exist in the tree.

Solution:

1 /**2 * Definition for binary tree3 * public class TreeNode {4 * int val;5 * TreeNode left;6 * TreeNode right;7 * TreeNode (int x) {val = x;}8  * }9  */Ten  Public classSolution { One      PublicTreeNode Buildtree (int[] Preorder,int[] inorder) { ATreeNode root = Buildtreerecur (preorder,inorder,0,preorder.length-1,0,inorder.length-1); -         returnRoot; -     } the  -      PublicTreeNode Buildtreerecur (int[] Preorder,int[] inorder,intPreS,intPreE,intInsintInE) { -         if(Pres>pree)return NULL; -         if(pres==PreE) { +TreeNode leaf =NewTreeNode (Preorder[pres]); -             returnLeaf; +         } A  at         intRootval =Preorder[pres]; -         intindex =InS; -          for(inti=ins;i<=ine;i++) -             if(inorder[i]==rootval) { -index =i; -                  Break; in             } -  to         intLeftlen = index-InS; +         intRightlen = InE-index; -     theTreeNode leftchild = Buildtreerecur (preorder,inorder,pres+1,pres+leftlen,ins,index-1); *TreeNode rightchild = Buildtreerecur (preorder,inorder,pree-rightlen+1,pree,index+1, InE); $TreeNode root =NewTreeNode (rootval);Panax NotoginsengRoot.left =Leftchild; -root.right=Rightchild; the         returnRoot; +    } A        the}

Construct Binary Tree from preorder and inorder traversal

Leetcode-construct Binary Tree from inorder and preorder travesal