PE14-1编程练习.exe 中的 0x58742258 (msvcp100d.dll) 处有未经处理的异常: 0xC0000005: 写入位置 0x00000

#include "stdafx.h"

#include <iostream>

#include <valarray>

#include <string>

#include <cstring>

using namespace std;



template <typename T1, typename T2>

class Pair

{

private:

    T1 a;

    T2 b;

public:

    T1 first() { return a; }

    T2 second() { return b; }

    Pair (const T1 & t1, const T2 & t2) : a (t1), b (t2) { }

	Pair () { }

};



class Wine

{

private:

    typedef valarray<int> ArrayInt;

    typedef Pair<ArrayInt, ArrayInt> PairArray;

    string label;

    int year;

    PairArray pa;

public:

    Wine (const char * l, int y, const int yr[], const int bot[]) 

        : label (l), year (y),  pa(ArrayInt(yr, year), ArrayInt(bot, year)) { }

	Wine (const char * l, int y) : label (l), year (y) { }

    void GetBottles();

	string & Label() { return label; }

    int Sum();

    void Show();

};



void Wine::GetBottles()

{

    cout << "Enter " << label << " data for " << year << " year(s):\n"; 

    for (int i = 0; i < year; i++)

    {

        cout << "Enter year: ";

        cin >> pa.first()[i];

        cout << "Enter bottles for that year: ";

        cin >> pa.first()[i];

    }

}

void Wine::Show()

{

    cout << "Wine: " << label << endl;

    cout.width(4);

    cout << "Year";

    cout << "    ";

    cout.width(7);

    cout << "Bottles" << endl;

    for (int i = 0; i < year; i++)

    {

        cout.width(4);

        cout << pa.first()[i];

        cout << "    ";

        cout.width(7);

        cout << pa.second()[i];

    }

}

int Wine::Sum()

{

    int sum = 0;

    for (int i = 0; i < year; i++)

    {

        sum += pa.first()[i];

    }

    return sum;

}





int main()

{

    cout << "Enter name of wine: ";

    char lab[50];

    cin.getline(lab, 50);

    cout << "Enter number of years: ";

    int yrs;

    cin >> yrs;



    Wine holding(lab, yrs); //stors label, years, give arrays yrs elements

    holding.GetBottles();

    holding.Show();



    const int YRS = 3;

    int y[YRS] = {1993, 1995, 1998};

    int b[YRS] = {48, 60, 72};

    //create new object, initialize using data in array;s ;y and b 

    Wine more("Gushing Grzpe Red", YRS, y, b);

    more.Show();

    cout << "Total bottles for " << more.Label() //use Label() method

        << ": " << more.Sum() << endl; //use sum() method

    cout << "Bye\n";

    return 0;

}