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题目：Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric: 1 / ... 阅读全文
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题目：Given a binary tree, return thelevel ordertraversal of its nodes' values. (ie, from left to right, level by level).For example:Given binary tree{3,... 阅读全文
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题目：Given a binary tree, return thezigzag level ordertraversal of its nodes' values. (ie, from left to right, then right to left for the next level and... 阅读全文
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题目：Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest... 阅读全文
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题目：Given preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree.解题思路：前序遍历序列的... 阅读全文
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题目：Given inorder and postorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree.解题思路：后序遍历的最... 阅读全文
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题目：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 ... 阅读全文
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题目：Given an array where elements are sorted in ascending order, convert it to a height balanced BST.解题思路：同链表的方法一样。一分为二，递归进行求解。代码： 1 /** 2 * Definitio... 阅读全文
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题目：Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.解题思路：注意是让构造平衡二叉搜索树。每次将链表从中间断开，分成左右两部分。... 阅读全文
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题目：Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the de... 阅读全文
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题目：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... 阅读全文
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题目：Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum... 阅读全文
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题目：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 andsu... 阅读全文
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题目：Given a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6The flattene... 阅读全文
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题目：Given a stringSand a stringT, count the number of distinct subsequences ofTinS.A subsequence of a string is a new string which is formed from the o... 阅读全文
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题目：Given a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next; }Populate each next poi... 阅读全文
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题目：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 s... 阅读全文
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题目：GivennumRows, generate the firstnumRowsof Pascal's triangle.For example, givennumRows= 5,Return[ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4... 阅读全文
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题目：Given an indexk, return thekthrow of the Pascal's triangle.For example, givenk= 3,Return[1,3,3,1].Note:Could you optimize your algorithm to use onl... 阅读全文
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题目：Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.For example, given the ... 阅读全文