如何计算文本文件中的哪一行单词是 C++

Question

I have an exercise in which I need to find words in a text file starting with user input symbol. I also need to determine in which line that word is and output that in text different text file. I managed to write code to output words starting with symbol and count word's position in text, but i cannot figure out how to count in which line that word is. Also i need to find those words which have symbols like ? ! etc. not only ' ' For example if i wanna find words starting with c then my program finds only "cerebral, cortex, could, create" but not "construct, capable, computers" from my example input which is below my code.

#include <iostream>
#include <fstream>
using namespace std;

int main() {

    fstream input;
    fstream output;
    string word, line;
    char startOfWord;

    cout << "I wanna find words starting with symbol: \n";

    cin >> startOfWord;

    int lineNumber = 0;

    input.open("f.txt");
    output.open("f1.txt");

    while (!input.eof()) {

        input >> word;
        lineNumber++;
        if (word.length() > 40) {
            continue;
        }
        if (word[0] == startOfWord) {
            output << word << ' ' << lineNumber << '\n';
        }
    }

    input.close();

    output.close();

    return 0;

}

Example input: user wanna find words starting with a .

f.txt :

A Stanford University project to?construct a model 
of the cerebral cortex in silicon could help scientists 
gain a better understanding of the brain, in order to 
create more,capable.computers and advanced 
neural prosthetics. 

Output: f1.txt

a 1
a 3
and 4
advanced 4

Answer 1

You are reading the file word by word, counting each word. You need to read the file line by line, counting each line, and then you can read words from each line.

Try this:

#include <iostream>
#include <fstream>
#include <sstream>
using namespace std;

int main() {
    ifstream input;
    ofstream output;
    string word, line;
    char startOfWord;

    cout << "I wanna find words starting with symbol: \n";

    cin >> startOfWord;

    int lineNumber = 0;

    input.open("f.txt");
    output.open("f1.txt");

    while (getline(input, line)) {
        ++lineNumber;
        istringstream iss(line);
        while (iss >> word) {
            if (word.length() > 40) {
                continue;
            }
            if (word[0] == startOfWord) {
                output << word << ' ' << lineNumber << '\n';
            }
        }
   }

    input.close();
    output.close();

    return 0;
}

Answer 2

I did it! This works!

#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
using namespace std;

void getWordsFromLine(string word, int index, vector<string> &memory) { //funkcija kas izvelk vardus no rindam
    string newWord;
    for (int i = index; i < word.length(); i++) {
        if (word[i] == ')' || word[i] == '(' || word[i] == '.' || word[i] == ',' || word[i] == '=' || word[i] == '?' || word[i] == '!') { //parbauda visas iespejamas pieturzimes
            i++;
            getWordsFromLine(word, i, memory);
            break;
        }
        else {
            newWord += word[i];
        }
    }
    memory.push_back(newWord);
}

int main() {
    int ok;
    do
    {
    ifstream input;
    ofstream output;
    string word, line;
    char startOfWord;
    char symbol;

    cout << "I wanna find words starting with symbol: \n";

    cin >> startOfWord;

    int lineNumber = 0;

    input.open("f.txt");
    output.open("f1.txt");

    while (getline(input, line)) {
        ++lineNumber;   //skaita rindas
        istringstream iss(line);
        while (iss >> word) {
            if (word.length() > 40) {
                continue;
            }
            vector<string> words;
            getWordsFromLine(word, 0, words);
            for (int i = 0; i < words.size(); i++) {
                if (words[i][0] == startOfWord) { //atrod vardus ar sakuma simbolu
                    output << words[i] << ' ' << lineNumber << '\n';
                }
            }
        }
    }

    input.close();
    output.close();
    cout<<"Vai turpinat (1) vai beigt (0)?"<<endl;
    cin>>ok;
    } while (ok==1);
    return 0;
}