c++ - 我不断收到相同的错误消息 : Segment Fault (core dumped)

Question

我对 C++ 和所有与计算机相关的东西都很陌生，所以不要着急。我第一次尝试在我类(class)的作业中使用 vector 。我设法编译了我的代码，但在运行到一半时，代码显示为 segment fault (core dumped)。我不知道如何使用 gdb 来查明确切的行，但我知道它出现在循环期间的名称函数中，以按字母顺序组织名称。我知道我的 vector 大小有问题，但我不知道如何修复它。我还需要一个简单的解决方案，因为我不是高级类，只能使用我目前在类里面学到的东西。

我也知道我为事物起的名字是多么愚蠢，事实上我在我的名字函数中塞满了太多东西......

请帮助我，尽管我的代码很困惑!

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

int choice(int);
void sortAndSend(vector<string> &names);

int main()
{
    ofstream outputFile;
    int numOfNames;
    int count = 0;
    numOfNames = choice(numOfNames);

    vector<string> names(numOfNames);
    sortAndSend(names);

    outputFile.close();
    return 0;
}

int choice(int a)
{
    cout << "Select a number 1-5 that reflects how many names" << endl
         << "you would like to enter." << endl;
    cin >> a;
    cout << "You have selected " << a << " names." << endl << endl;
    return a;
}

void sortAndSend(vector<string> &names)
{
    ofstream outputFile;
    string name;
    string a;

    cout << "You will be asked to enter " << names.size() << " names." << endl
         << "You may enter each individual's "
         << "last name first, followed by the individual's first name, "
         << "then middle name (if applicable)." << endl
         << "Do NOT include any commas." << endl << endl;
    cin.ignore();
    for (int count = 0; count < names.size(); count++)                           //Allows user to enter specified # of names
    {
        cout << "Enter a name now: ";
        getline(cin, name);
        names[count] = name;
        cout << endl << "You have entered " << names[count] << endl << endl;
    }

    for (int count = 0; count < names.size(); count++)
    {
        cout << names[count] << endl;
    }
    for (int count = 0; count < names.size(); count++)
                                      //Arranges names in alphabetical order
                                      //Error occurs here
    {
        while (names[count] > names[count + 1])
        {
            a = names[count + 1];
            names[count + 1] = names[count];
            names[count] = a;
        }
    }
    cout << "Your names are now alphebetized" << endl << endl;
    cout << "This is what is being copied to the file named"
         << " 'AlphabeticalOrderEC.txt': " << endl;

    for (int count = 0; count < names.size(); count++)         //Prints     names in alphabetical order
    {
        cout << names[count] << endl;
    }

    outputFile.open("AlphabeticalOrderEC");                    //Prints names into file
    for (int count = 0; count < names.size(); count++)
    {
        outputFile << names[count] << endl;
    }
}

Answer 1

您尝试访问不属于 vector 的地址。查看代码的这一部分:

for (int count = 0; count < names.size(); count++)
{
    while (names[count] > names[count + 1])
    {
        a = names[count + 1];
        names[count + 1] = names[count];
        names[count] = a;
    }
}

你应该使用count + 1，只有当count小于names.size()-1时你才必须这样做。您应该找到另一个可以替换这部分代码的逻辑。这就像试图访问只有 10 个元素的数组的第 11 个元素。