BrookLearnData

摘要： 题目; Given inorder and postorder traversal of a tree, construct the binary tree. 题意及分析：给出棵二叉树的中序遍历和后续遍历，求这棵树。同用先序和中序推二叉树，不同的点是，后序遍历的最后一个点才是根节点。 代码： 阅读全文

摘要： 题目： Given preorder and inorder traversal of a tree, construct the binary tree. 题意及分析：给出一棵树的先序遍历和中序遍历，要求给出给出该二叉树。先序遍历第一个节点肯定是根节点，那么这样就可以利用中序遍历找出树的左右子树， 阅读全文

摘要： 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 farthe 阅读全文

摘要： 题目： Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tre 阅读全文

摘要： 题目： Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is sy 阅读全文

摘要： 题目： Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identic 阅读全文

摘要： 题目： Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains 阅读全文

摘要： 题目: All DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: "ACGAATTCCG". When studying DNA, it is sometimes useful 阅读全文

摘要： 题目：Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elemen 阅读全文

摘要： 题目：Given an array of integers, every element appears three times except for one, which appears exactly once. Find that single one. 题意及分析：找出数组中出现一次的数，其 阅读全文