EXC_BAD_ACCESS（代码= 1，地址= 0x0）问题

Question

我是C ++的新手，被要求编写一个字典程序，该程序将.txt文件作为数据加载并将其加载到数据结构中，以作为字典进行处理和发挥作用。我已经用Java成功编写了该程序，因此已将其作为指南将程序转换为C ++。我的程序崩溃了：

string tempkey = myvector [0];

有什么想法或解决方案吗？

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <sstream>
#include <map>
#include <list>
#include <algorithm>

using namespace std;
void replaceAll(string &s, const string &search, const string &replace);
string replaceWordSearch(string word);

int main() {
    string line;
    ifstream file("Data.CS.SFSU.txt");
    map<string, vector<string>> mymap;

    if (file.is_open()) {
        cout << "! Opening data file... ./Data.CS.SFSU.txt" << endl;
        cout << "! Loading data..." << endl;

        while (getline(file, line)) {
            istringstream ss(line);
            string token;
            vector<string> myvector;
            vector<string> newvector;
            vector<string> finalvector;

            while (getline(ss, token, '|')) {
                myvector.push_back(token);
            }

            for (int i = 1; i < myvector.size(); i++) {
                newvector.push_back(myvector[i]);
            }

            //the word key value ERROR LINE
            string tempkey = myvector[0];

            for (int i = 0; i < newvector.size(); i++) {
                string temp = newvector[i];
                replaceAll(temp, "=>", " ");
                replaceAll(temp, "noun ", "[noun] : ");
                replaceAll(temp, "adjective ", "[adjective] : ");
                replaceAll(temp, "verb ", "[verb] : ");
                finalvector.push_back(temp);
            }

            mymap.insert(make_pair(tempkey, finalvector));
        }

        file.close();
        cout << "! Loading completed..." << endl;
        cout << "! Closing data file... ./Data.CS.SFSU.txt" << endl;
    }

    cout << endl;
    cout << "----- DICTIONARY 340 C++----- " << endl;
    cout << endl;

    vector<string> keyWords;

    for (map<string, vector<string>>::iterator it = mymap.begin(); it != mymap.end(); it++) {
        keyWords.push_back(it->first);
    }

    while (true) {
        cout << "Search: ";
        string input;
        getline(cin, input);

        if (input == "") {
            cout << " |" << endl;
            cout << " <Please enter a search key (and a part of speech).>" << endl;
            cout << " |" << endl;
        }
        else {
            for (int i = 0; i < input.length(); i++) {
                input[i] = tolower(input[i]);
            }

            istringstream s2(input);
            vector<string> v;
            string tmp;

            while (s2 >> tmp) {
                v.push_back(tmp);
            }


            string wordSearch = v[0];
            wordSearch = replaceWordSearch(wordSearch);

            if ((v[0] == "!Q") || (v[0] == "!q")) {
                cout << endl;
                cout << "----- THANK YOU----- " << endl;
                break;
            }
            else {

                cout << " |" << endl;

                if (v.size() == 0) {
                    cout << " <Please enter a search key (and a part of speech).>" << endl;
                }

                if (v.size() == 1) {
                    if (find(keyWords.begin(), keyWords.end(), v[0]) != keyWords.end()) {
                        for (auto map_iter = mymap.cbegin(); map_iter != mymap.cend(); ++map_iter) {
                            if (v[0] == map_iter->first) {
                                for (auto vec_iter = map_iter->second.cbegin(); vec_iter != map_iter->second.cend(); ++vec_iter)
                                    std::cout << " " << wordSearch << " " << *vec_iter << endl;
                            }
                        }
                    }
                    else {
                        cout << " <Not found.>" << endl;

                    }
                }

                if (v.size() == 2) {
                    if ((v[1] != "noun") && (v[1] != "adjective") && (v[1] != "verb")) {
                        cout << " <2nd argument must be a part of speech.>" << endl;
                    }
                    else {
                        if (find(keyWords.begin(), keyWords.end(), v[0]) != keyWords.end()) {
                            for (auto map_iter = mymap.cbegin(); map_iter != mymap.cend(); ++map_iter) {
                                if (v[0] == map_iter->first) {
                                    if ((v[1] == "noun") || (v[1] == "adjective") || (v[1] == "verb")) {
                                        int count = 0;
                                        for (auto vec_iter = map_iter->second.cbegin(); vec_iter != map_iter->second.cend(); ++vec_iter) {
                                            string str1 = *vec_iter;
                                            string str2 = v[1];
                                            if (str1.find(str2) != string::npos) {
                                                std::cout << " " << wordSearch << " " << *vec_iter << endl;
                                                count++;
                                            }
                                        }
                                        if (count == 0) {
                                            cout << " <Not found.>" << endl;
                                        }
                                    }
                                    else {
                                        cout << " <Not found.>" << endl;
                                    }
                                }
                            }
                        }
                        else {
                            cout << " <Not found.>" << endl;
                        }
                    }
                }
                if (v.size() > 2) {
                    cout << " <Please enter a search key (and a part of speech).>" << endl;
                }
                cout << " |" << endl;
            }
        }
    }
    return 0;
}
void replaceAll(string &s, const string &search, const string &replace) {
    for (size_t pos = 0; ; pos += replace.length()) {
        // Locate the substring to replace
        pos = s.find(search, pos);
        if (pos == string::npos) break;
        // Replace by erasing and inserting
        s.erase(pos, search.length());
        s.insert(pos, replace);
    }
}

string replaceWordSearch(string word) {
    if (word == "book")
        return "Book";
    if (word == "bookable")
        return "Bookable";
    if (word == "bookbinder")
        return "Bookbinder";
    if (word == "bookcase")
        return "Bookcase";
    if (word == "csc210")
        return "CSC210";
    if (word == "csc220")
        return "CSC220";
    if (word == "csc340")
        return "CSC340";
    else
        return word;
}