Question

    //**************************************************************************************************************
// FILE: a04.cpp
//**************************************************************************************************************
#include <fstream>
#include <iostream>
#include "Sorter.hpp"
using namespace std;
// Write the function header for Merge ()
void Merge(int a[] , int b[],int c[], int n)
{
    int i = 0, j = 0, k = 0;
    while (i < n || j < n) {
        // Write the if-elseif-elseif-... statement in the body of the while loop
        if (i < n  && j < n && a<=b) {
                c = a;
                i++;
        }
        else if (i < n && j < n && a > b) {
            c =b;
            j++;
        }
        else if (i < n) {
            c = a;
            i++;
        }
        else {
            c =b;
            j++;
        }
        k++;
    } // end while
} // end function merge

void ReadList(ifstream fin, int a[], int n);

void ReadFile(int a[], int b[], int& n)
{
    ifstream fin ("ints-in.txt");
    ReadList(fin,a,n); // come back again different than the psuedo code
    ReadList(fin,b,n);
    fin.close();
} 


// Write the function header for ReadList()
void ReadList(ifstream fin, int a[], int n)
{
    n = 0;
    int number;
    // Implement the sentinel loop
    while (fin >> number && number != -1) {
        a[n] = number;
        n++; // come back again
    }
}


void WriteFile(int a[], int n)
{
    ofstream fout("ints-out.txt");
    // Write a vary loop where variable ivaries from 0 to n - 1. In the loop send a[i] and ' ' to fout.
    for (int i =0; i <= n-1; i++) {
        fout << a << ' '; // come back again.
    }
    fout << -1;
    fout.close();
}


int main()
{
// Define int arrays a,b, and c and int variable n.
int a[100], b[100], c[200];
int n;

// Call ReadFile () passing a,b, and n
ReadFile(a,b,n);

// Define and create a Sorter object named sorter
Sorter sorter;
// Call SelectionSort() on sorter to sort a into ascending order.
// Hint: to access the ASCENDING constant data member of the Sorter class you write Sorter::ASCENDING.
sorter.SelectionSort(a,100,Sorter::ASCENDING); //come back again here.

// Call BubbleSort () on sorter to sort b into ascending order
sorter.BubbleSort(b,100,Sorter::ASCENDING);
// Call Merge() passing a,b,c, and n
Merge(a,b,c,n);
// Call WriteFile () passing c and 2n
WriteFile(c,2*n);

return 0;
}

我不知道为什么无法编译。

错误1错误C2248： 'std :: basic_ifstream＆lt; _Elem，_Traits＆gt; :: basic_ifstream'：无法访问私人成员在课堂上宣布 '的std :: basic_ifstream＆LT; _Elem，_Traits＆GT;' C：\用户\希沙姆\文档\ Visual studio 2012 \ projects \ homework4 \ a04.cpp 39 1 Homework4错误2错误 C2248：'std :: basic_ifstream＆lt; _Elem，_Traits＆gt; :: basic_ifstream'：不能访问类中声明的私有成员 '的std :: basic_ifstream＆LT; _Elem，_Traits＆GT;' C：\用户\希沙姆\文档\ Visual studio 2012 \ projects \ homework4 \ a04.cpp 40 1 Homework4 3 IntelliSense： “std :: basic_ifstream＆lt; _Elem，_Traits＆gt; :: basic_ifstream（const std :: basic_ifstream＆lt; _Elem，_Traits＆gt; :: _ Myt＆amp; _Right）[with _Elem = char， _Traits = std :: char_traits]“（在”C：\ Program Files（x86）\ Microsoft Visual Studio 11.0 \ VC \ include \ fstream“的第827行声明）无法访问c：\ Users \ Hisham \ Documents \ Visual Studio 2012 \ Projects \ Homework4 \ a04.cpp 39 11家庭作业4 4智能感知： “std :: basic_ifstream＆lt; _Elem，_Traits＆gt; :: basic_ifstream（const std :: basic_ifstream＆lt; _Elem，_Traits＆gt; :: _ Myt＆amp; _Right）[with _Elem = char， _Traits = std :: char_traits]“（在”C：\ Program Files（x86）\ Microsoft Visual Studio 11.0 \ VC \ include \ fstream“的第827行声明）无法访问c：\ Users \ Hisham \ Documents \ Visual Studio 2012 \ Projects \ Homework4 \ a04.cpp 40 11 Homework4

感谢。

Answer 1

该错误并未说明ifstream无法访问。它（以其自己的复杂方式）说复制构造函数是不可访问的，因为它被声明为私有。问题是你通过值传递ifstream，它试图调用无法访问的拷贝构造函数。

void ReadList(ifstream fin, int a[], int n)

通过引用传递它。

void ReadList(ifstream & fin, int a[], int n)

Answer 2

iostream不可复制，因此无法按值传递它们。

Answer 3

void ReadFile(int a[], int b[], int& n)
{
    ifstream fin ("ints-in.txt");
    ReadList(fin,a,n); // come back again different than the psuedo code
    ReadList(fin,b,n);
    fin.close();
} 

void ReadList(ifstream fin, int a[], int n)

您正在尝试按副本传递istream实例。你不能那样做 - 复制构造函数被标记为私有。

您需要将ReadList函数声明为：

void ReadList(ifstream& fin, int a[], int n)

Answer 4

我一直在研究这个相同的代码，我在Merge（）函数中有不同的东西。

void Merge(int a[], int b[], int c[], int& n)
 {
   int i = 0, j = 0, k = 0;
   while (i < n || j < n) 
 {
    if (i < n && j < n && a[i] <= b[j])
     {c[k] = a[i];
    i++;}
    else if (i < n  && j < n && a[i] > b[j])
     {c[k] = b[j];
     j++;}
    else if (i < n)
    {c[k] = a[i];
    i++;}
     else
     {c[k] = b[j];
    j++;}
    k++;
      }
  }

我把i，j和k放在括号中。我不确定这是否正确，但我在这方面没有任何错误消息。

无法编译c ++代码，因为ifstream不可访问

4 个答案: