我在这些函数上得到编译器错误：
编译器抱怨我的vector上的push_front（），以及我试图在map上使用的运算符++。
我只想在前面添加一个向量元素，并分别添加一个新的map条目。

LanguageModel countSequence(LanguageModel &model, vector<string> &Seq) {    
    //append start and end to the vector of strings    
    vector<string>::iterator v = Seq.begin();    
    Seq.front();    
    Seq.("<START>");    
    v = Seq.end();    
    Seq.push_back("<END");    
    v = Seq.begin();

    //create word pairs    
    vector<string> pairs;     
    for (int n = 0; n <= Seq.size(); n++) {    
    pairs.at(n) = buildPair(Seq[n], Seq[n+1]);

    } 

    //feed each word to map 1 with number of times it was seen    
    for (int m = 0; m <= Seq.size(); m++) {    
    ++model.firstCounts[Seq[m]];    
    model.firstCounts[Seq[m]] =  count(Seq.begin(), Seq.end(), Seq[m]);

    }   

    //feed each word pair and the number of times it was seen    
    for (int k = 0; k <= Seq.size(); k++) {    
    ++model.pairCounts[Seq[k]];    
    model.pairCounts[Seq[k]] =  count(Seq.begin(), Seq.end(), Seq[k]);    
    }

    //feed each unique first word in a word pair and the second words in the pairs

    for (int l = 0; l <= Seq.size(); l++) {    
    istringstream iss(pairs[l]);    
     string sub;    
        iss >> sub;    
     string sub2;    
        iss >> sub2;   

        if (Seq[l] = sub) {    
            ++model.follows[sub];    
            model.follows[sub].push_back(sub2);     
        } 

    }

return model;    
}

string genNext(LanguageModel &model2, string &testWord, int Number) {    
    //use results of countSequence     
    string numbers[20]= model2.follows[testWord];    
    return numbers[Number];

}

以下是错误：

LangModel.cpp: In function ‘LanguageModel countSequence(LanguageModel&, std::vector<std::basic_string<char> >&)’:
LangModel.cpp:38:6: error: ‘class std::vector<std::basic_string<char> >’ has no member named ‘push_front’
Seq.push_front("<START>");

l.cpp:69:25: error: could not convert ‘(&(& Seq)->std::vector<_Tp, _Alloc>::operator[]<std::basic_string<char>, std::allocator<std::basic_string<char> > >(((std::vector<std::basic_string<char> >::size_type)l)))->std::basic_string<_CharT, _Traits, _Alloc>::operator=<char, std::char_traits<char>, std::allocator<char> >((*(const std::basic_string<char>*)(& sub)))’ from ‘std::basic_string<char>’ to ‘bool’
if (Seq[l] = sub) {
                                     ^
LangModel.cpp:70:10: error: no match for ‘operator++’ (operand type is ‘std::map<std::basic_string<char>, std::list<std::basic_string<char> > >::mapped_type {aka std::list<std::basic_string<char> >}’)
++model.follows[sub];
                      ^
LangModel.cpp: In function ‘std::string genNext(LanguageModel&, std::string&, int)’:
LangModel.cpp:81:45: error: conversion from ‘std::map<std::basic_string<char>, std::list<std::basic_string<char> > >::mapped_type {aka std::list<std::basic_string<char> >}’ to non-scalar type ‘std::string {aka std::basic_string<char>}’ requested
string numbers[20]= model2.follows[testWord];
                                                     ^