Question

我有一个家庭作业，我需要修改旧作业才能使用模板。

原始赋值要求对动态分配的整数数组进行随机排序，我需要创建一个将其扩展为字符串和双精度的模板。我正在使用while循环和switch-case向用户显示一个菜单，在那里他们可以决定他们使用哪种类型并填充数组。

我试图尽可能减少这种情况，使调试更容易。整数实现没有编译器错误，但是double和string变量没有。

int* pPresortedInts = NULL; //pointer to array of ints
std::cout << std::endl << "How many integers did you want to sort? ";
std::cin >> sizeOfArray;
pPresortedInts = new int[sizeOfArray]; //dynamically allocate array

//prompt user to fill array
std::cout << std::endl << "Great! Please enter " << sizeOfArray << " numbers: ";
for (int counter = 0; counter < sizeOfArray; counter++) {
    std::cin >> pPresortedInts[counter];
}

//output filled array
std::cout << std::endl << std::endl << "Here are the integers in their original order: ";
for (int counter = 0; counter < sizeOfArray; counter++) {
    std::cout << std::endl << pPresortedInts[counter];
}
std::cout << std::endl << std::endl;

//shuffle elements and print the result
shuffleSort(pPresortedInts, sizeOfArray);

//Remember to delete dynamically allocated arrays
delete [] pPresortedInts;
pPresortedInts = NULL;

双重实施：

double* pPresortedDoubles = NULL; //pointer to array of doubles
std::cout << std::endl << "How many doubles did you want to sort? ";
std::cin >> sizeOfArray;
pPresortedDoubles = new double[sizeOfArray]; //dynamically allocate array

//prompt user to fill array
std::cout << std::endl << "Great! Please enter " << sizeOfArray << " numbers: ";
for (int counter = 0; counter < sizeOfArray; counter++) {
    std::cin >> pPresortedDoubles[counter];
}

//output filled array
std::cout << std::endl << std::endl << "Here are the doubles in their original order: ";
for (int counter = 0; counter < sizeOfArray; counter++) {
    std::cout << std::endl << pPresortedDoubles[counter];
}
std::cout << std::endl << std::endl;

//shuffle elements and print the result
shuffleSort(pPresortedDoubles, sizeOfArray);

//Remember to delete dynamically allocated arrays
delete [] pPresortedDoubles;
pPresortedDoubles = NULL;

最后，这是模板本身：

template <class T>
void shuffleSort(T pPresortedArray[], T size) {
    T* pShuffledArray = new T[size]; // pointer to dynamically allocated array of a generic type
    T randomElement;
    T temp;

    //fill ShuffledArray with PresortedArray
    for (int counter = 0; counter < size; counter++) {
        pShuffledArray[counter] = pPresortedArray[counter];
    }

    for (int counter = 0; counter < size; counter++) {
        randomElement = rand()%size; // choose a random element from the ShuffledArray array
        //swap that element with the currently selected counter
        temp = pShuffledArray[randomElement];
        pShuffledArray[randomElement] = pShuffledArray[counter];
        pShuffledArray[counter] = temp;
    }
    std::cout << "Shuffled array: ";
    //print the (hopefully) shuffled array
    for (int counter = 0; counter < size; counter++) {
        std::cout << std::endl << pShuffledArray[counter];
    }
    std::cout << std::endl << std::endl;

    //Delete dynamically allocated array within scope
    delete [] pShuffledArray;
    pShuffledArray = NULL;
}

我在函数调用时尝试了specifying the type，但是没有修复错误。我不相信我的问题与taking arguments by reference有任何关系。

我倾向于选择Gist来阅读代码，所以我上传了entire program there以及作业说明（以防某些方面有用）。

感谢您的帮助！

Answer 1

好吧这似乎不对

void shuffleSort(T pPresortedArray[], T size) {

为什么要模拟数组的大小，它总是为size_t

void shuffleSort(T pPresortedArray[], size_t size) {

我怀疑你用'T'全局替换'int'： - ）

Answer 2

您的数组大小应为size_t或int，但无论如何都不应为T：）

除此之外，它是一段相当不错的代码。

您可以使用std::swap来简化它。

此外，您的输入代码也可以很容易地制作成模板，以避免重复。

Answer 3

在这一行：

void shuffleSort(T pPresortedArray[], T size)

你真的希望参数大小的类型是T。

你可以使用 std :: random_shuffle random_shuffle API 和一个新的API

std::shuffle API

C ++'没有用于调用'模板的匹配函数

3 个答案: