17.13 Consider a simple node-like data structure called BiNode, which has pointers to two other nodes. The data structure BiNode could be used to represent both a binary tree (where nodel is the left node and node2 is the right node) or a doubly link…

17.2 Design an algorithm to figure out if someone has won a game oftic-tac-toe. 这道题让我们判断玩家是否能赢井字棋游戏,有下面几点需要考虑: 1. 判断是否能赢hasWon函数是调用一次还是多次,如果是多次,我们可能为了优化而需要加入一些预处理. 2. 井字棋游戏通常是3x3的大小,我们是否想要实现NxN的大小? 3. 我们需要在代码紧凑,执行速度和代码清晰之间做出选择. #include <iostream> #…

17.14 Oh, no! You have just completed a lengthy document when you have an unfortunate Find/Replace mishap. You have accidentally removed all spaces, punctuation, and capitalization in the document. A sentence like "I reset the computer. It still didn…

17.12 Design an algorithm to find all pairs of integers within an array which sum to a specified value. 这道题实际上跟LeetCode上的Two Sum很类似,但是不同的是,那道题限定了只有一组解,而这道题说可以有很多组符合要求的解,那么我们先来看一种使用哈希表的解法,这种解法的时间复杂度是O(n),空间复杂度是O(1),思路是用哈希表建立每个数字和其下标之间的映射,遍历整个数字,如果targ…

17.11 Implement a method rand7() given rand5(). That is, given a method that generates a random number between 0 and 4 (inclusive), write a method that generates a random number between 0 and 6 (inclusive). 这道题说给了我们一个rand5()函数,可以生成0到4之间的随机数,让我们写一个函数r…

17.10 Since XML is very verbose, you are given a way of encoding it where each tag gets mapped to a pre-defined integer value. The language/grammar is as follows: Element --> Tag Attributes END Children END Attribute --> Tag Value END --> 0 Tag -…

17.9 Design a method to find the frequency of occurrences of any given word in a book. 这道题让我们找书中单词出现的频率,那么首先需要搞清楚的问题是,只需要统计一个单词,还是多个单词.如果是一个单词的话,那直接就遍历所有单词直接统计即可,如果是多个,就需要建立哈希表来建立每个单词和其出现次数之间的映射,然后再来查找即可,参见代码如下: unordered_map<string, int> make_dicti…

17.8 You are given an array of integers (both positive and negative). Find the contiguous sequence with the largest sum. Return the sum. LeetCode上的原题,请参见我之前的博客Maximum Subarray. 解法一: int get_max_sum(vector<int> nums) { int res = INT_MIN, sum = INT_MI…

17.7 Given any integer, print an English phrase that describes the integer (e.g., "One Thousand, Two Hundred Thirty Four"). LeetCode上的原题,请参见我之前的博客Integer to English Words. string convert_hundred(int num) { vector<string> v1{"", &…

17.6 Given an array of integers, write a method to find indices m and n such that if you sorted elements m through n, the entire array would be sorted. Minimize n - m (that is, find the smallest such sequence). 为了更好的理解题意,我们通过一个例子来分析,比如我们有如下的数组: 1, 2,…