C++类中的has-a关系和is-a关系

时间: 2023-12-18 07:03:22 浏览: 73
has-a关系是指类中包含了其他类的对象作为自己的成员变量,表示一个类拥有另外一个类的实例。比如一个汽车类可以包含一个引擎类的对象作为自己的成员变量,表示汽车拥有一个引擎。 is-a关系是指类之间的继承关系,表示一个类是另外一个类的一种特殊形式。比如一个圆形类可以继承自一个图形类,表示圆形是一种图形。在C++中,使用关键字“extends”来表示继承关系。
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sudo ./bootstrap --------------------------------------------- CMake 3.8.1, Copyright 2000-2017 Kitware, Inc. and Contributors Found GNU toolchain C compiler on this system is: gcc C++ compiler on this system is: g++ Makefile processor on this system is: make g++ is GNU compiler g++ has setenv g++ has unsetenv g++ does not have environ in stdlib.h g++ has stl wstring g++ has <ext/stdio_filebuf.h> --------------------------------------------- make: 'cmake' is up to date. CMake Error: The current CMakeCache.txt directory /home/GPU_Project/ARM-Mali-G72/Software_packet/DDK-Compile_Tool/cmake/cmake-3.8.1/CMakeCache.txt is different than the directory /home/test/GPU_Project/ARM-Mali-G72/Software_packet/DDK-Compile_Tool/cmake/cmake-3.8.1 where CMakeCache.txt was created. This may result in binaries being created in the wrong place. If you are not sure, reedit the CMakeCache.txt --------------------------------------------- Error when bootstrapping CMake: Problem while running initial CMake ---------------------------------------------

这个错误信息提示是在运行 CMake 过程中出现了问题,可能是由于 CMakeCache.txt 文件所在的目录不一致导致的。建议检查一下 CMakeCache.txt 文件所在的目录是否正确,并且尝试清空 CMake 缓存重新运行 bootstrap。你可以尝试以下命令: ``` rm -rf CMakeCache.txt sudo ./bootstrap ``` 如果还有问题,可以提供更多的错误信息,以便更好地帮助你解决问题。

Given a pair of positive integers, for example, 6 and 110, can this equation 6 = 110 be true? The answer is yes, if 6 is a decimal number and 110 is a binary number. Now for any pair of positive integers N1​ and N2​, your task is to find the radix of one number while that of the other is given. Input Specification: Each input file contains one test case. Each case occupies a line which contains 4 positive integers: N1 N2 tag radix Here N1 and N2 each has no more than 10 digits. A digit is less than its radix and is chosen from the set { 0-9, a-z } where 0-9 represent the decimal numbers 0-9, and a-z represent the decimal numbers 10-35. The last number radix is the radix of N1 if tag is 1, or of N2 if tag is 2. Output Specification: For each test case, print in one line the radix of the other number so that the equation N1 = N2 is true. If the equation is impossible, print Impossible. If the solution is not unique, output the smallest possible radix. 用c++写代码 并且要考虑radix大于36的情况

您想解决一个关于进制转换的问题,其中需要确定一个数字的进制,而另一个数字的进制已知。您希望用C++编写代码,并且要考虑进制大于36的情况。以下是一个可能的实现: ```cpp #include <iostream> #include <string> #include <cmath> using namespace std; int charToInt(char c) { if (isdigit(c)) { return c - '0'; } else { return c - 'a' + 10; } } long long convertToDecimal(string num, int radix) { long long result = 0; int power = 0; for (int i = num.length() - 1; i >= 0; i--) { result += charToInt(num[i]) * pow(radix, power); power++; } return result; } int findRadix(string num, long long target) { char maxDigit = *max_element(num.begin(), num.end()); int minRadix = charToInt(maxDigit) + 1; // Smallest possible radix // Binary search to find the radix int left = minRadix; int right = max(36, minRadix); // Consider radix larger than 36 while (left <= right) { int mid = (left + right) / 2; long long converted = convertToDecimal(num, mid); if (converted == target) { return mid; } else if (converted < target) { left = mid + 1; } else { right = mid - 1; } } return -1; // Impossible } int main() { string N1, N2; int tag, radix; cin >> N1 >> N2 >> tag >> radix; if (tag == 1) { long long decimalN2 = convertToDecimal(N2, radix); int resultRadix = findRadix(N1, decimalN2); if (resultRadix == -1) { cout << "Impossible" << endl; } else { cout << resultRadix << endl; } } else { long long decimalN1 = convertToDecimal(N1, radix); int resultRadix = findRadix(N2, decimalN1); if (resultRadix == -1) { cout << "Impossible" << endl; } else { cout << resultRadix << endl; } } return 0; } ``` 这个程序首先定义了一个`charToInt`函数,用于将字符转换为对应的整数值。然后,`convertToDecimal`函数将给定进制的数字转换为十进制数。最后,`findRadix`函数使用二分查找来确定另一个数字的进制。在主函数中,根据输入的`tag`值选择相应的计算方法,并输出结果。 希望这可以帮助到您!如果您有任何其他问题,请随时问我。
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Write a computer program that could be used to track, by lab, which user is logged into which computer: Lab Number Computer Station Numbers 1 1-5 2 1-6 3 1-4 4 1-3 ➢ You run four computer labs. Each lab contains computer stations that are numbered as the above table. ➢ Each user has a unique ID number. The ID starting with three characters (for example, SWE or DMT), and followed by three digits (like, 001). ➢ Whenever a user logs in, the user’s ID, lab number, and the computer station number are transmitted to your system. For example, if user SWE001 logs into station 2 in lab 3, then your system receives (SWE001, 2, 3) as input data. Similarly, when a user SWE001 logs off a station, then your system receives the user id SWE001. ➢ If a user who is already logged into a computer attempts to log into a second computer, display "invalid login". If a user attempts to log into a computer which is already occupied, display "invalid login". If a user who is not included in the database attempts to log out, display "invalid logoff". 输入格式 If user SWE001 is logged into station 2 in lab 3 and user DMT001 is logged into station 1 of lab 4, use + for logging in, - for logging off, and = for end of input: + SWE001 2 3 + DMT001 1 4 《面向对象程序设计 C++》 2022-2023 春季学期 2 / 4 - SWE001 = 输出格式 The status of all labs (who is logged into which computer). Otherwise, display invalid login or invalid logoff. You need to display the status of all labs even when the input is invalid.

请按以下描述,自定义数据结构,实现一个circular bufferIn computer science, a circular buffer, circular queue, cyclic buffer or ring buffer is a data structure that uses a single,fixed-size buffer as if it were connected end-to-end. This structure lends itself easily to bufering data streams. There were earlycircular buffer implementations in hardware. A circular buffer first starts out empty and has a set length. In the diagram below is a 7-element buffeiAssume that 1 is written in the center of a circular buffer (the exact starting locatiorimportant in a circular buffer)8Then assume that two more elements are added to the circulal2buffers use FIFOlf two elements are removed, the two oldest values inside of the circulal(first in, first out) logic. n the example, 1 8 2 were the first to enter the cremoved,leaving 3 inside of the buffer.If the buffer has 7 elements, then it is completely full6 7 8 5 3 4 5A property of the circular buffer is that when it is full and a subsequent write is performed,overwriting the oldesdata. In the current example, two more elements - A & B - are added and theythe 3 & 475 Alternatively, the routines that manage the buffer could prevent overwriting the data and retur an error or raise an exceptionWhether or not data is overwritten is up to the semantics of the buffer routines or the application using the circular bufer.Finally, if two elements are now removed then what would be retured is not 3 & 4 but 5 8 6 because A & B overwrote the 3 &the 4 yielding the buffer with:

Dog Card is a card game. In the game, there are a total of 2n cards in the deck, each card has a value, and the values of these 2n cards form a permutation of 1 ~ 2n. There is a skill that works as follows: 1. Draw a card from the top of the deck. 2. If the deck is empty, then skip to step 3, otherwise you guess whether the card on the top of the deck has a higher value than your last drawn card and draw a card from the top of the deck. If your guess is correct, then repeat this step, otherwise skip to step 3. 3. End this process. Nana enjoys playing this game, although she may not be skilled at it. Therefore, her guessing strategy when using this skill is simple: if the value of the last drawn card is less than or equal to n, then she guesses that the next oard's valve is higher, ther wse, she guedses thet the next card's vaue s lomler she wârns tb dmokt tor anfafrhlm decks of cards (Obviously, there are (2n)! cases), how many cards she can draw in total if she uses the skill only once in each case. Since this number can be very large,please provide the answer modulo a given value.Dog Card is a card game. In the game, there are a total of 2n cards in the deck, each card has a value, and the values of these 2n cards form a permutation of 1 ~ 2n. There is a skill that works as follows: 1. Draw a card from the top of the deck. 2. If the deck is empty, then skip to step 3, otherwise you guess whether the card on the top of the deck has a higher value than your last drawn card and draw a card from the top of the deck. If your guess is correct, then repeat this step, otherwise skip to step 3. 3. End this process. Nana enjoys playing this game, although she may not be skilled at it. Therefore, her guessing strategy when using this skill is simple: if the value of the last drawn card is less than or equal to n, then she guesses that the next oard's valve is higher, ther wse, she guedses thet the next card's vaue s lomler she wârns tb dmokt tor anfafrhlm decks of cards (Obviously, there are (2n)! cases), how many cards she can draw in total if she uses the skill only once in each case. Since this number can be very large,please provide the answer modulo a given value.给出c++代码及中文解释

用C++编写程序,实现以下问题2、题目ID Codes(POJ1146) Time Limit: 1000MS Memory Limit: 10000K 描述: It is 2084 and the year of Big Brother has finally arrived, albeit a century late. In order to exercise greater control over its citizens and thereby to counter a chronic breakdown in law and order, the Government decides on a radical measure--all citizens are to have a tiny microcomputer surgically implanted in their left wrists. This computer will contains all sorts of personal information as well as a transmitter which will allow people's movements to be logged and monitored by a central computer. (A desirable side effect of this process is that it will shorten the dole queue for plastic surgeons.) An essential component of each computer will be a unique identification code, consisting of up to 50 characters drawn from the 26 lower case letters. The set of characters for any given code is chosen somewhat haphazardly. The complicated way in which the code is imprinted into the chip makes it much easier for the manufacturer to produce codes which are rearrangements of other codes than to produce new codes with a different selection of letters. Thus, once a set of letters has been chosen all possible codes derivable from it are used before changing the set. For example, suppose it is decided that a code will contain exactly 3 occurrences of a', 2 of b' and 1 of c', then three of the allowable 60 codes under these conditions are: abaabc abaacb ababac These three codes are listed from top to bottom in alphabetic order. Among all codes generated with this set of characters, these codes appear consecutively in this order. Write a program to assist in the issuing of these identification codes. Your program will accept a sequence of no more than 50 lower case letters (which may contain repeated characters) and print the successor code if one exists or the message No Successor' if the given code is the last in the sequence for that set of characters. 输入: Input will consist of a series of lines each containing a string representing a code. The entire file will be terminated by a line consisting of a single #. 输出: Output will consist of one line for each code read containing the successor code or the words 'No Successor'. 样例输入 abaacb cbbaa # 样例输出 ababac No Successor

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