随笔分类 -  Tree

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Recover Binary Search Tree
摘要：Two elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Ref:http://fisherlei.blogspot.com/20... 阅读全文
posted @ 2014-02-20 15:24 Razer.Lu 阅读(238) 评论(0) 推荐(0)
Binary Tree Postorder Traversal
摘要：Given a binary tree, return thepostordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3return[3,2,1].Note:Recursive solution is trivial, could you do it iteratively?Ref:http://www.cnblogs.com/feiling/p/3426486.html[解题思路]后序遍历的非递归相对来说比较难，根节点需要在其左右孩子都访问结束后... 阅读全文
posted @ 2014-02-17 17:14 Razer.Lu 阅读(200) 评论(0) 推荐(0)
Binary Tree Preorder Traversal
摘要：Given a binary tree, return thepreordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3return[1,2,3].Note:Recursive solution is trivial, could you do it iteratively?Using Stack/** * Definition for binary tree * public class TreeNode { * int val; * ... 阅读全文
posted @ 2014-02-17 17:08 Razer.Lu 阅读(209) 评论(0) 推荐(0)
Flatten Binary Tree to Linked List
摘要：Given a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6The flattened t... 阅读全文
posted @ 2014-02-17 13:34 Razer.Lu 阅读(249) 评论(0) 推荐(0)
Binary Tree Level Order Traversal II
摘要：Given a binary tree, return thebottom-up level ordertraversal of its nodes' values. (ie, from left to right, level by level from leaf to root).For example:Given binary tree{3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7return its bottom-up level order traversal as:[ [15,7] [9,20], [3],] 解题思... 阅读全文
posted @ 2014-02-17 13:20 Razer.Lu 阅读(200) 评论(0) 推荐(0)
Unique Binary Search Trees II
摘要：Givenn, generate all structurally uniqueBST's(binary search trees) that store values 1...n.For example,Givenn= 3, your program should return all 5 uni... 阅读全文
posted @ 2014-02-17 02:55 Razer.Lu 阅读(173) 评论(0) 推荐(0)
Unique Binary Search Trees
摘要：Givenn, how many structurally uniqueBST's(binary search trees) that store values 1...n?For example,Givenn= 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 ... 阅读全文
posted @ 2014-02-17 02:32 Razer.Lu 阅读(216) 评论(0) 推荐(0)
Binary Tree Maximum Path Sum
摘要：Given a binary tree, find the maximum path sum.The path may start and end at any node in the tree.For example:Given the below binary tree, 1 ... 阅读全文
posted @ 2014-02-17 01:29 Razer.Lu 阅读(208) 评论(0) 推荐(0)
Populating Next Right Pointers in Each Node
摘要：Given a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next; }Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set toNULL.Initially, all next pointers are set toNULL.N... 阅读全文
posted @ 2014-02-15 02:54 Razer.Lu 阅读(183) 评论(0) 推荐(0)
Populating Next Right Pointers in Each Node II
摘要：Follow up for problem "Populating Next Right Pointers in Each Node".What if the given tree could be any binary tree? Would your previous solution stil... 阅读全文
posted @ 2014-02-15 02:52 Razer.Lu 阅读(213) 评论(0) 推荐(0)
Path Sum II
摘要：Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.For example:Given the below binary tree andsum =... 阅读全文
posted @ 2014-02-14 10:38 Razer.Lu 阅读(178) 评论(0) 推荐(0)
Construct Binary Tree from Inorder and Postorder Traversal
摘要：Given inorder and postorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree.后续遍历 根节点在最后一个元... 阅读全文
posted @ 2014-02-12 06:57 Razer.Lu 阅读(177) 评论(0) 推荐(0)
Construct Binary Tree from Preorder and Inorder Traversal
摘要：Given preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree.ref:http://fish... 阅读全文
posted @ 2014-02-12 06:50 Razer.Lu 阅读(224) 评论(0) 推荐(0)
Convert Sorted Array to Binary Search Tree
摘要：Convert Sorted Array to Binary Search TreeGiven an array where elements are sorted in ascending order, convert it to a height balanced BST./** * Definition for binary tree * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */pub... 阅读全文
posted @ 2014-02-06 03:50 Razer.Lu 阅读(165) 评论(0) 推荐(0)
Convert Sorted List to Binary Search Tree
摘要：Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.Ref:http://www.cnblogs.com/feiling/p/3267... 阅读全文
posted @ 2014-02-03 01:39 Razer.Lu 阅读(303) 评论(0) 推荐(0)
Sum Root to Leaf Numbers
摘要：Given a binary tree containing digits from0-9only, each root-to-leaf path could represent a number.An example is the root-to-leaf path1->2->3which rep... 阅读全文
posted @ 2014-02-01 09:19 Razer.Lu 阅读(163) 评论(0) 推荐(0)
Binary Tree Level Order Traversal
摘要：[解题思路]记录下一层元素个数，这样每次遍历时就知道何时结束，只需一个queue用一个count来计数每一层的node的个数，/** * Definition for binary tree * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */public class Solution { public ArrayList> levelOrder(TreeNode root) { ... 阅读全文
posted @ 2014-02-01 08:31 Razer.Lu 阅读(197) 评论(0) 推荐(0)
Binary Tree Zigzag Level Order Traversal
摘要：[解题思路]二叉树的层序遍历通过使用queue来实现，上网搜索了下，发现该题可以使用栈来解决，通过分析执行结果确实是后进先出这里通过定义leftToRight来表示是从左到右还是从右到左从左到右：先加left后加right从右到左：先加right后加leftorderlevel traversal 遍历最后每行添加到result前 判断是leftToRight 还是Right to Left/** * Definition for binary tree * public class TreeNode { * int val; * TreeNode left; * Tr... 阅读全文
posted @ 2014-02-01 08:05 Razer.Lu 阅读(188) 评论(0) 推荐(0)
Binary Tree Inorder Traversal
摘要：Given a binary tree, return theinordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3return[1,3,2].Note:Recursive solution is trivial, could you do it iteratively?Recursive Version/** * Definition for binary tree * public class TreeNode { * int val;... 阅读全文
posted @ 2014-02-01 03:05 Razer.Lu 阅读(209) 评论(0) 推荐(0)
Minimum Depth of Binary Tree
摘要：Given a binary tree, find its minimum depth.The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node./** * Definition for binary tree * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { v... 阅读全文
posted @ 2014-02-01 02:08 Razer.Lu 阅读(147) 评论(0) 推荐(0)

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