Question

我写了一个从用户那里接受问题的程序。然后，它将该问题与预定义问题列表进行匹配，并返回答案。它应该是准确的，只与接近（模糊匹配）或用户输入的问题匹配。

我的SSSCE：

代码：

#include <iostream>
#include <cstdint>
#include <algorithm>
#include <numeric>
#include <functional>

int min_index(const std::vector<int>& list)
{
    int index = 0;
    int smallest = list[0];

    for (size_t i = 0; i < list.size(); ++i) {
        if (list[i] < smallest) {
            smallest = list[i];
            index = i;
        }
    }
    return index;
}

std::uint32_t LevenshteinDistance(const std::string &First, const std::string &Second)
{
    const std::size_t FirstLength = First.size();
    const std::size_t SecondLength = Second.size();

    std::vector<std::uint32_t> Current(SecondLength + 1);
    std::vector<std::uint32_t> Previous(SecondLength + 1);

    std::size_t I = 0;
    std::generate(Previous.begin(), Previous.end(), [&] {return I++; });

    for (I = 0; I < FirstLength; ++I)
    {
        Current[0] = I + 1;

        for (std::size_t J = 0; J < SecondLength; ++J)
        {
            auto Cost = First[I] == Second[J] ? 0 : 1;
            Current[J + 1] = std::min(std::min(Current[J] + 1, Previous[J + 1] + 1), Previous[J] + Cost);
        }

        Current.swap(Previous);
    }
    return Previous[SecondLength];
}

std::vector<std::string> questions = 
{
    "What is the most popular program at GBC?",
    "How much is the tuition at GBC?",
    "Do I have to pay my fees before I can register?",
    "What are my fee payment options?",
    "How do I know when I'm allowed to register?",
    "How do I add and/or drop courses from my timetable?",
    "What do I do if I can't find my PASSWORD?",
    "How do I withdraw from a program?",
    "What are the college policies?",
    "How much math do I need to know?",
    "What is the program code for computer programming?",
    "What is stu-view?",
    "What is the college best known for?",
    "How easy is it to find work after program completion?",
    "What if I plan to continue my education after?"
};

std::vector<std::string> answers =
{
    "Fashion",
    "3000 a semester",
    "Yes you have to pay the fees before registering",
    "You may pay online on your student account through the student portal",
    "You may register two weeks or more before the start of the program",
    "You may drop courses from online through the student portal",
    "You can call ... and an agent will assist you",
    "You may withdraw using the student portal online",
    "They are located at the following link...",
    "It depends on the program you are entering",
    "T127 is the code for computer science",
    "Stu-View is a student portal to manage student account and view marks.",
    "The cafeteria food",
    "Depends on the field of work and timing",
    "You may do so within three years after program completion"
};

int main()
{
    std::string user_question = "program";

    std::vector<int> distances = std::vector<int>(questions.size(), 0);

    for (size_t I = 0; I < questions.size(); ++I)
    {
        int dist = LevenshteinDistance(user_question, questions[I]);
        distances[I] = dist;
    }

    std::cout<<"Distance:      "<<distances[min_index(distances)]<<"\n";
    std::cout<<"User-Question: "<<user_question<<"\n";
    std::cout<<"Question-Key:  "<<questions[min_index(distances)]<<"\n";
    std::cout<<"Answer-Value:  "<<answers[min_index(distances)]<<"\n";

    return 0;
}

所以在上面，用户输入"program" ..它应该从问题列表中找到最接近的匹配并返回相应的答案..

然而，它打印：

Distance:      17
User-Question: program
Question-Key:  What is stu-view?
Answer-Value:  Stu-View is a student portal to manage student account and view marks.

它应该有更好的结果或准确性，但它似乎并不关心句子是否具有用户输入的关键字：S它适用于小型案例但适用于大型数据库或上述那里是超过5个句子，它很难...特别是关键词很少; l

我做错了什么？任何想法我如何解决它并使其更准确？我尝试过HammingDistance，类似的结果..

Answer 1

与其他字符串相比，"program"和"What is stu-view?"都很短。尽管单词"program"很常见，但将"What is stu-view?"转换为"program"比将"What is the most popular program at GBC?"转换为"program"更容易。

我做错了什么？

我认为你做错了什么。如果您对结果不满意，这意味着您当前的形式主义（最小化Levenshtein距离）不是您想要的。

您可以寻求更多本地解决方案：例如对字符串进行标记，计算单词之间的成对Levenshtein距离然后合并结果（平均值，sup inf ...）

更好的解决方案需要做一些参考书目（可能是无监督的机器学习主题）

最接近的字符串/句子匹配算法不起作用？

1 个答案: