Question

WRITE A C++ PROGRAM TO IMPLEMENT THE CONCEPT OF INDEX (Create index in text file) full code

Answer 1

C++ PROGRAM TO IMPLEMENT THE CONCEPT OF INDEX is provided below with the output screen:

// This header file includes every header file
#include<bits/stdc++.h>
using namespace std;

// Keeping the file name as documents
const string FILE_NAME = "documents.txt";

vector<string> File_Lines(string file) 
{
    ifstream in(FILE_NAME);
    vector<string> lines;
    for (string line; getline(in, line); ) 
    {
        lines.push_back(line);
    }
    return lines;
}

string get_input() 
{
    // Initializing string variable
    string str;
    getline(cin, str);
    return str;
}

int main()
 {
    // reads the contents on line
    vector<string> lines = File_Lines(FILE_NAME);

    // open an output stream to append new lines
    ofstream fileOut(FILE_NAME, ios::app);

    long long t;

    cout<<"Enter the number of line you want with index: "<<endl;
    cin>>t;
    for (int n = 0; n < t; n++)
     {
        // get a line from the user
        cout << "> ";
        std::string t = get_input();

        // finding it in the vector of lines
        auto it = std::find(lines.begin(), lines.end(), t); 
        
        if (it == lines.end()) 
        {
            // if the line was not found then append it
            fileOut << t << endl; 
            lines.push_back(t);   
            cout << "Line \"" << t << "\" is indexed.\n";
        }
         else 
         {
            // the line was found then this is the index.
            int index = it - lines.begin();
            cout << "Line \"" << t << "\" was found at index: " << index << ".\n";

            // getting the adjacent line
            int indexx;
            if (index%2 == 0) 
            {
                // if the index is even then get the next line
                indexx = index + 1;
            } 
            else
             {
                // odd index, get the previous line
                indexx = index - 1;
            }
            if (indexx < lines.size())
             {
                string line2 = lines[indexx]; // the text of the adjacent line
                cout << "Adjacent line: \"" << line2 << "\" (index " << indexx << ")\n";
            } 
            else 
            {
                cout << "No adjacent line is found yet!\n";
            }
        } // ends if the line was found 
    } // ends for t times

    cout << endl;
    get_input();

    return 0;
}

Output screen:

Now the file named "Documents" will be created with the lines entered by the user indexed in it.

Thank you!!! Good luck! Keep Coding :)