c++ - 如何使用动态大小的结构数组？

Question

我得做作业了。它是控制台应用程序，它使用一组结构来保存有关计算机的信息(品牌、制造年份、重量和库存编号)。所以我写了一个完整的工作程序，但我想使用动态数组，因为我不知道用户将输入多少条记录。

有没有办法做到这一点。要在数组中添加新记录直到用户说 n/N？有什么建议吗？

这是我的程序版本:

#include "stdafx.h"
#include <iostream>

using namespace std;

struct ComputerInfo
{
    char computerMark[20], invertarNumber[6];
    unsigned int year;
    float weight;
};

ComputerInfo computerArray[300];

ComputerInfo AddComputers(ComputerInfo compterArray[], int counter)
{
    cout << "Enter mark of the computer: ";
    cin >> computerArray[counter].computerMark;

    cout << "Enter year of establish: ";
    cin>> computerArray[counter].year;

    while ((computerArray[counter].year < 1973)
        || (computerArray[counter].year > 2013))
    {
        cout << "INVALID YEAR!!!" << endl;

        cout << "Enter year of establish: ";
        cin>> computerArray[counter].year;
    }

    cout << "Enter computer weidth: ";
    cin >> computerArray[counter].weight;

    cout << "Enter computer invertar number(up to six digits): ";
    cin >> computerArray[counter].invertarNumber;

    return computerArray[counter];
}

void ShowRecords()
{
    int counter = 0;

    while (computerArray[counter].year != 0)
    {
        cout << "Mark: " << computerArray[counter].computerMark << endl;
        cout << "Year: " << computerArray[counter].year << endl;
        cout << "Weidth: " << computerArray[counter].weight << endl;
        cout << "Inv. number: " << computerArray[counter].invertarNumber << endl << endl;

        counter++;
    }
}

void MoreThanTenYearsOld(ComputerInfo computerArray[])
{
    int counter = 0;
    float counterOldComputers = 0;
    float computerPer = 0;

    while (computerArray[counter].year == 0)
    {
        if (computerArray[counter].year <= 2003)
        {
            counterOldComputers++;
        }

        counter++;
    }

    computerPer = counterOldComputers / 3;

    cout << endl;
    cout << "Percantage of old computers is: " << computerPer << endl;
}

int main()
{
    int counter = 0;
    float computerPer = 0;
    char answer = 'y';

    for (int i = 0; i <= 299; i++)
    {
        strcpy(computerArray[i].computerMark,"");
    }

    while((answer == 'Y') || (answer == 'y'))
    {
        computerArray[counter] = AddComputers(computerArray, counter);
        cout << endl;
        cout << "Do you want to enter more records (Y/N): ";
        cin >> answer;
        cout << endl;
        counter++;
    }

    MoreThanTenYearsOld(computerArray);

    return 0;
}

Answer 1

是的。而不是你的阵列，使用

std::vector<ComputerInfo> computerArray;

您可以根据需要添加任意数量的对象:

ComputerInfo c;
// read the data
computerArray.push_back(c);

现在，computerArray[0]将在 c 中获得信息.

您需要 #include <vector> .

此外，而不是 char computerMark[20]你可以使用 std::string .