我应该如何从 2 个单独的文本文件中读取字符串并比较匹配项？

您的示例代码有很多问题，逐一完成确实是一项漫长的任务。您需要从文件中读取行并在矢量中动态填充文本。然后，您不需要指定数组的大小。此外，您应该检查如何在 C++ 中使用循环。 但以下是您正在尝试的示例代码。通读代码并阅读注释以理解，并根据您的用例进行尝试。首先尝试一个小示例，然后尝试实际的文本文件。

#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

void compareFiles(const std::string& fileA, const std::string& fileB, const std::string& matchFile, const std::string& nonMatchFile) 
{
    std::ifstream inputFile1(fileA);
    std::ifstream inputFile2(fileB);
    std::ofstream outputFileMatch(matchFile);
    std::ofstream outputFileNonMatch(nonMatchFile);

    std::vector<std::string> masterList;  // to save the master list
    std::string line;

    // Read contents of fileA into a vector assuming each line has the text you want to match
    while (std::getline(inputFile1, line)) // reading until end of file
    {
        masterList.push_back(line); // push into the vector
    }

    // Compare contents of fileB with text from fileA in vector masterList
    while (std::getline(inputFile2, line)) // reading until end of file
    {
        if (std::find(masterList.begin(), masterList.end(), line) != masterList.end()) // check if the text in fileB is present in the fileA vector
        {
            outputFileMatch << line << "\n"; // write if match found
        } 
        else 
        {
            outputFileNonMatch << line << "\n"; // write if match not found
        }
    }

}

编辑：正如@john在评论中正确指出的那样，不需要关闭文件，因为它们会自动超出范围。所以删除了那个代码。

不确定我是否正确理解了您的问题。 这是逐行读取文件的代码。

如果第一个文件“in.txt”中的行存在于字典文件“dic.txt”中，则将行写入“foundItmes.txt”，否则将其写入“remainintItmes.txt”。

#include <algorithm>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <iterator>
#include <string>
#include <unordered_set>

class LineHelper {
    std::string data;

public:
    friend std::istream& operator>>(std::istream& is, LineHelper& l);
    operator std::string() const { return data; }
};

std::istream& operator>>(std::istream& is, LineHelper& l)
{
    return std::getline(is, l.data);
}

using LineInputStreamIter = std::istream_iterator<LineHelper>;

std::unordered_set<std::string> loadDictionary(std::istream& in)
{
    return { LineInputStreamIter { in }, {} };
}

std::unordered_set<std::string> loadDictionary(const std::filesystem::path& p)
{
    std::ifstream f { p };
    return loadDictionary(f);
}

void partitionCopy(std::istream& in, std::unordered_set<std::string> dic, std::ostream& trueOut, std::ostream& falseOut)
{
    std::partition_copy(
        LineInputStreamIter { in }, {},
        std::ostream_iterator<std::string> { trueOut, "\n" },
        std::ostream_iterator<std::string> { falseOut, "\n" },
        [&dic](const auto& s) { return dic.count(s) != 0; });
}

void partitionCopy(const std::filesystem::path& in, const std::filesystem::path& dic, const std::filesystem::path& trueOut, const std::filesystem::path& falseOut)
{
    std::ifstream inF { in };
    std::ofstream trueOutF { trueOut };
    std::ofstream falseOutF { falseOut };
    partitionCopy(inF, loadDictionary(dic), trueOutF, falseOutF);
}

int main()
{
    partitionCopy("in.txt", "dic.txt", "foundItmes.txt", "remainintItmes.txt");
    return 0;
}

https://godbolt.org/z/73e4h46d3

没有正确测试，但应该可以正常工作。

在大家的帮助下，我能够找到问题的正确答案，谢谢。该函数正在查找 vComp 的第一个元素与其最后一个元素范围内的任何匹配项。这很重要，因为如果以相反的顺序比较文件，则只会找到匹配项。这是因为将仅包含匹配的字符串，而不包含其余的不匹配数据。在将选定组与整体进行比较时，这始终是正确的。find()string linestring line

//Variable Declaration
ifstream inData_Master, inData_Comp;
ofstream outData_Match, outData_NonMatch;
int num_Matches = 0, num_NonMatches = 0; // counter
vector<string> vComp; // saves the compare list
string line;

inData_Master.open("Input_File_Master.txt");
inData_Comp.open("Input_File_Comp.txt");
outData_Match.open("Output_File_Match.txt");
outData_NonMatch.open("Output_File_NonMatch.txt");

// Reads & saves contents of our Comp input file, which will be compared against the Master file, store in line
while (getline(inData_Comp,line)) 
{
    vComp.push_back(line); // Adds new element to the end of the Vector via line
}
// Reads the contents of the master file 
while (getline(inData_Master, line))
{
    if (find(vComp.begin(),vComp.end(),line) != vComp.end()) // if nonMatch, find = vComp.end()  
    {
        outData_Match << line << endl; // match found
        num_Matches++; // counts match
    }
    else
    {
        outData_NonMatch << line << endl; // match not found
        num_NonMatches++; // counts non match
    }
}
cout << "Matches: " << num_matches << endl;
cout << "NonMatches: " << num_NonMatches << endl;