string find_first does not update string

string find_first does not update string

本文关键字：string not update does first find      更新时间：2023-10-16

嘿，我有一个小问题，这个程序工作正常

它接受一个字符串测试，替换所有的"!"，并确定"?"answers"。"在哪里，然后将does值放在一个向量上，并只打印字符串中作为问题的部分，如果字符串中没有任何"!"，则正常工作，但如果有，则无法识别所有问题。

如果字符串是这样的，它可以工作

std::string test ("ver. what? lol. o que e isto? nao sei. ola? haha. why? adeus. oi! an? haha. lool! ");

但是如果是这样，它就找不到问题。

std::string test ("ver! what? lol! o que e isto? nao sei! ola? haha. why? adeus. oi! an? haha. lool! ");

但是这部分的颂歌应该用"代替所有的"!"。

while (found!=std::string::npos)
{
  //std::cout << found << 'n';
  test[found]='.';
  found=test.find_first_of("!",found+1);
  std::cout << test << 'n';
}

Thanks for the help

#include <fstream>
#include <iostream>
#include <string>
#include <vector>
#include <cstddef>
using namespace std;
int main ()
{
    std::vector< int > interrogation ;
    std::vector< int > dot;
    string look = "?";
    string look_again = ".";
    std::string test ("ver! what? lol! o que e isto? nao sei! ola? haha. why? adeus. oi! an? haha. lool! ");
    std::size_t found = test.find_first_of("!");
    string::size_type pos = test.find(look);
    string::size_type sop = test.find(look_again);
    while (found!=std::string::npos)
    {
        //std::cout << found << 'n';
        test[found]='.';
        found=test.find_first_of("!",found+1);
        std::cout << test << 'n';
    }
    std::cout << test << 'n';
    while (pos != std::string::npos)
    {
        int a = pos ;
        //cout << " . found at : " << sop << std::endl;
        interrogation.push_back(a);
        string fragment = test.substr (0 , pos  );    // works
        //cout << fragment << endl ;
        pos = test.find(look, pos + 1);
    }
    while (sop != std::string::npos)
    {
        int b = sop;
        //cout << " ? found at : " << pos << std::endl;
        dot.push_back(b);
        string fragment2 = test.substr (0 , sop) ;    // works
        //cout << fragment2 << endl ;
        sop = test.find(look_again, sop + 1);
    }
    while( interrogation.size() > 0){
        std::cout << test << 'n';
        while(dot.back() > interrogation.back())
        {
            cout << "dot.pop_back" << endl;
            dot.pop_back();
        }
        string fragment = test.substr (dot.back() + 1,  interrogation.back() -     dot.back());
        cout << "question with dot n" << fragment << endl ;
        interrogation.pop_back() ;
    }
}

在用. (-> while (found!=std::string::npos) { ... })替换!之前，您正在寻找第一个.位置(-> string::size_type sop = test.find(look_again);)。在将!替换为.的while循环之后对sop进行赋值。

如果有人想要它，这里是固定的代码，该代码在分配给名为questions_to_find的文本文件的字符串中查找问题，并将问题保存到名为saved_question的文本文件

#include <fstream>
#include <iostream>
#include <string>
#include <vector>
#include <cstddef>
using namespace std;
int main (){
std::vector< int > interrogation ;
std::vector< int > dot;
string look = "?";
string look_again = ".";
std::string test;

  ifstream myfile ("questions_to_find.txt");
    while ( getline (myfile,test) )
    {
      cout << test << 'n';
    }
    myfile.close();
std::size_t found = test.find_first_of("!");
  while (found!=std::string::npos)
  {
    //std::cout << found << 'n';
    test[found]='.';
    found=test.find_first_of("!",found+1);
    //std::cout << test << 'n';
  }
string::size_type pos = test.find(look);
string::size_type sop = test.find(look_again);
while (pos != std::string::npos)
{
int a = pos ;
//cout << " . found at : " << sop << std::endl;
interrogation.push_back(a);
string fragment = test.substr (0 , pos  );    // works
//cout << fragment << endl ;
  pos = test.find(look, pos + 1);
}
while (sop != std::string::npos)
{
int b = sop;
//cout << " ? found at : " << pos << std::endl;
dot.push_back(b);
string fragment2 = test.substr (0 , sop) ;    // works
//cout << fragment2 << endl ;
  sop = test.find(look_again, sop + 1);
}
std::cout << test << 'n';
while( interrogation.size() > 0){
//std::cout << test << 'n';
while(dot.back() > interrogation.back())
{
    //cout << "dot.pop_back" << endl;
   dot.pop_back();
}
string fragment = test.substr (dot.back() + 1,  interrogation.back() -     dot.back());
cout << "Question found. n" << fragment << endl ;
// to save text
string save = "saved_question.txt" ;
ofstream myfile;
myfile.open (save.c_str(), ios::app);
myfile <<  fragment << endl;
myfile.close();
//cout << "Question saved in text file" << endl;
interrogation.pop_back() ;
}
}

如果您的目标是输出字符串中的句子是问题，我认为您在那里做了太多的工作，当您做查找"replace '!' with '。'， find '?’，然后在多个循环中输出作为问题的句子。

只执行一个循环从整个字符串中获取问题。

void function(string str) {
    string sentence = "";
    for(int i=0; i < str.length(); i++) {
      if(str[i] == '.' || str[i] == '!')
        sentence = ""; // the sentence is not a question so clear the sentence
      else if(str[i] == '?') {
        sentence.push_back(str[i]);
        cout << sentence << endl;
      }
      else
        sentence.push_back(str[i]);
    }
}

我不太明白为什么你要在一个向量中存储标点符号(.?)或它的索引(在字符串中)。也许有一个更简单的方法来解析/分割需要显示的字符串?

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