从一个字符串中获取2-5个连续的单词短语我得到了2个工作但却无法做到3

Question

vector <string> oneWordPhrase;
vector <string> twoWordPhrase;
vector <string> threeWordPhrase;

vector<string>::iterator it1;
vector<string>::iterator it2;

string str="hello my is bob oh hey jay oh";

string split = str;
string word;
stringstream stream(split);
while( getline(stream, word, ' ') )
{
  oneWordPhrase.push_back(word);
}//used to split sentence into words

for(it1=oneWordPhrase.begin(); it1!=oneWordPhrase.end(); it1++)
{
    if(it1+1 == oneWordPhrase.end())
        break;
    twoWordPhrase.push_back(*it1 + ' ' + *(it1+1));
}//getting two word phrases

cout<<"two word---------------\n";
for(int i=0; i<twoWordPhrase.size(); i++)
    cout<<twoWordPhrase[i]<<endl;

for(it1=twoWordPhrase.begin(); it1!=twoWordPhrase.end(); it1++)
{
    it2=oneWordPhrase.begin()+2;
    threeWordPhrase.push_back(*it1 + ' ' + *it2);
    ++it2;  /* was hoping that I can get each word after "is" but it 
             didn't allow me. the problem is here */
}//getting three word phrases
cout<<"three word---------------\n";

for(int i=0; i<twoWordPhrase.size(); i++)
    cout<<threeWordPhrase[i]<<endl;

我得到了两个正确的打印，这是

你好我的

我的

是bob

鲍勃哦

哦，嘿嘿

嘿杰伊

jay oh

然而，我的threeWordPhrase打印出来

你好我的

我的是

是鲍勃是

鲍勃哦是

哦，嘿是

嘿杰伊是

jay oh is

对于threeWordPhrases我希望打印“你好我是”“我的鲍勃”“是bob哦”“鲍勃哦嘿”一直到“嘿杰伊哦”。

我在myWordPhrase.begin（）+ 2指出了我的it2，并希望它会像在数组中那样增加1，但事实并非如此。

我评论了给我问题的代码部分

我很确定如果我能找出3个单词短语我可以做4个和5个单词短语，所以对3个单词的任何帮助都会非常感激！

Answer 1

执行*it2 = oneWordPhrase.begin() + 2 时，它始终会为您提供oneWordPhrase向量中的第3个成员。您可以使用计数器而不是迭代器，因为您需要遍历两个向量：

vector <string> oneWordPhrase;
vector <string> twoWordPhrase;
vector <string> threeWordPhrase;

vector<string>::iterator it1;
vector<string>::iterator it2;

string str="hello my is bob oh hey jay oh";

string split = str;
string word;
stringstream stream(split);
while( getline(stream, word, ' ') )
{
  oneWordPhrase.push_back(word);
}//used to split sentence into words

for(it1=oneWordPhrase.begin(); it1!=oneWordPhrase.end(); it1++)
{
    if(it1+1 == oneWordPhrase.end())
        break;
    twoWordPhrase.push_back(*it1 + ' ' + *(it1+1));
}//getting two word phrases

cout<<"two word---------------\n";
for(int i=0; i<twoWordPhrase.size(); i++)
    cout<<twoWordPhrase[i]<<endl;

for(int i=0; i!=twoWordPhrase.size() - 2; i++)
{
    threeWordPhrase.push_back( twoWordPhrase[i] + ' ' + oneWordPhrase[i + 2] );
      /* was hoping that I can get each word after "is" but it 
             didn't allow me. the problem is here */
}//getting three word phrases
cout<<"three word---------------\n";

for(int i=0; i<twoWordPhrase.size() - 2; i++)
    cout<<threeWordPhrase[i]<<endl;