C++ std::bad_alloc error with std::vector

我知道这个问题以前有人问过，但答案似乎对提问者的代码太具体了。

如果这被认为是一个无用的重复问题，请随时将其删除或标记为重复。

据我所知，我的代码对于我试图实现的目标是正确的，即计算文本文件中指定单词的出现次数。我将不胜感激任何帮助，谢谢。

错误

    This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc

我的主要部分.cpp（导致问题）

    //vectors to hold words from two files
vector<string> wordlist;
vector<string> file;
vector<int> searchVec;
//while a is not an empty string
while (a != "") {
    //getNextWord() returns each word in order from a text file
    //a is a play script, b is a list of words to search for
    a = infile.getNextWord();
    b = infile2.getNextWord();
    file.push_back(a);
    //counts total words in play script
    count++;
    //increments and adds each word from the list of words to search for to the vector
    for (int i = 0; b != ""; i++) {
        wordlist.push_back(b);
    }
    //cycles through words to search for
    for (int j = 0; j < wordlist.size(); j++) {
        //cycle through te play script
        for (int k = 0; k < file.size(); k++) {
            //if the current play script word is the same as the test word, up the count
            if (file[k] == wordlist[j]) {
                searchCount++;
            }
        }
        //print appropriate output, re-initialise the count to 0 for the next word
        cout << "The word " << wordlist[j] << " occurs " << searchCount << " times." << endl;
        searchCount = 0;
    }
}