Construct String from Binary Tree
发布时间:2020-12-14 04:42:06 所属栏目:大数据 来源:网络整理
导读:You need to construct a string consists of parenthesis and integers from a binary tree with the preorder traversing way. The null node needs to be represented by empty parenthesis pair "()". And you need to omit all the empty parenthesis p
You need to construct a string consists of parenthesis and integers from a binary tree with the preorder traversing way. The null node needs to be represented by empty parenthesis pair "()". And you need to omit all the empty parenthesis pairs that don‘t affect the one-to-one mapping relationship between the string and the original binary tree. Example 1: Input: Binary tree: [1,2,3,4] 1 / 2 3 / 4 Output: "1(2(4))(3)" ? Example 2: Input: Binary tree: [1,null,4] 1 / 2 3 4 Output: "1(2()(4))(3)" 1 public class Solution { 2 public String tree2str(TreeNode root) { 3 if (root == null) return ""; 4 String rootValue = String.valueOf(root.val); 5 String leftValue = tree2str(root.left); 6 String rightValue = tree2str(root.right); 7 8 if (leftValue.equals("") && rightValue.equals("")) { 9 return rootValue; 10 } else if (leftValue.equals("")) { 11 return String.format("%s()(%s)",rootValue,rightValue); 12 } else if (rightValue.equals("")) { 13 return String.format("%s(%s)",leftValue); 14 } else { 15 return String.format("%s(%s)(%s)",leftValue,rightValue); 16 } 17 } 18 } (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |