需要帮助更正家庭作业代码，C++ input/output

Question

我正在学习 Comp Sci 的第一门课程。我的任务是输入一个 .txt 文件，然后输出一个修改后的 .txt 文件。我遇到的第一个问题只是修复目录。我做到了，.txt 文件一切正常，除了教授说我在 switch 语句中有错误。

#include <fstream>
#include <iostream>
using namespace std;

int main()
{
    int s = -2, a = 0, b = 0, NumIn;

    ifstream inFile("NumbersIn.txt");
    if (inFile.fail()) {
        cout << "Unable to open file" << endl;
        return -1;
    }

    ofstream outFile("RevisedNumbers.txt");
    while (!inFile.eof()) {
        inFile >> NumIn;
        cout << NumIn << endl;
        if (NumIn < 0)
            NumIn = -1;
        else if (NumIn > 0)
            NumIn = 1;
        outFile << NumIn << endl;
        switch (NumIn) {
        case -1:
            a += s;
            break;
        case 0:
            s += 1;
        case 1:
            b += s;
        }
    }
    outFile.close();
    inFile.close();
    cout << "A = " << a << endl;
    cout << "B = " << b << endl;
    cout << "S = " << s << endl;

    return 0;
}

输出：

 0
 -2
 9
 14
 -22
 12
 6
 -9
 12
 13
 -33
 21
 9
 0
 1
 2
 3
 4
 1
 A = -4
 B = -9
 S = 0
 Program ended with exit code: 0

我在这里包括作业问题，所以我使用 s、a 和 b 作为整数的原因：

You program will require the following files
Input file: NumbersIn.txt (attached to this assignment)
Output file: RevisedNumbers.txt
You program will use the following variables:
int s=-2, a = 0, b = 0. NumIn;
As long as there is data in the input file, your program will read a number into the variable NumIn, print it on the screen, and then determine the following:
If NumIn is negative change it to -1
If NumIn is positive change it to +1
If NumIn is zero, do nothing
Write the new value of NumIn to the output file RevisedNumbers
After updating NumIN, use a switch statement to based on the current value of NumIn
When NumIn is -1 increase the value of A by S
When NumIn is 0 increment S by 1
When NumIn is 1 increase the value of B by S
When you no longer have data to read in print out the current value of A, B and S.

Submit a copy of your program.
The screen output
The input file.
The output file.

Answer 1

您的版本：

    switch (NumIn) {
    case -1:
        a += s;
        break;
    case 0:
        s += 1;
    case 1:
        b += s;
    }

要修复它，请添加两个 break 语句：

    switch (NumIn) {
    case -1:
        a += s;
        break;
    case 0:
        s += 1;
        break;
    case 1:
        b += s;
        break;
    }

如果没有它们，案例 0 会跳转到案例 1。这样做实际上是合法的，但被认为是一个常见错误，因此如果您的失败是故意的，您应该始终发表评论。我想这次应该不是。

需要帮助更正家庭作业代码，C++ input/output

Need help correcting Homework code, C++ input/output

c++

switch-statement