Q5(i).cpp

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

bool check( vector <string> text ,vector<string> pattern){
    long text_size = text.size();                           // size of text vector
    long pattern_size = pattern.size();                     // size of pattern vector
    if( text_size  < pattern_size ) {
        // if size of pattern is greater than size of text , then it's not possible to search pattern in text. so return false
        return false;
    }
    int itr1 = 0;                                           // for text pointer
    int itr2 = 0;                                           // for pattern pointer
    while(itr1 < text_size && itr2 < pattern_size ) {
        if( text[itr1].compare(pattern[itr2]) == 0 ) {            // if matched , then increment both pointer
            itr1++;
            itr2++;
        }
        else {
            itr1++;                                         // otherwise increment text pointer only
        }
    }
    if ( itr2 == pattern_size ) {
        // if pattern pointer is equal to size of pattern , then pattern exists in the text
        return true;
    }
    else {
        // otherwise text does not contain pattern
        return false;
    }
}


int main() {
    // text_file.txt and pattern_file.txt and this program should be in the same file.
    // reading from text_file.txt and storing it in text vector
    vector <string> text;
    ifstream myfile1 ("text_file.txt");
    if ( myfile1 ) {
        string line;
        while ( getline (myfile1 , line) ) {
            string temp = "";
            for(int i = 0; i < line.length(); ++i) {
                if( line.substr(i,3).compare(" , ") != 0) {  // getting ' , ' then store it
                    temp += line[i];
                }
                else {
                    text.push_back(temp);
                    temp = "";
                    i = i + 2;
                }

            }
        }
        myfile1.close();
    }
    else {
        cout << "\nUnable to open text file\n";
    }
    
    // reading from pattern_file.txt and storing it in pattern vector
    vector <string> pattern;
    ifstream myfile2 ("pattern_file.txt");
    if (myfile2) {
        string line;
        while ( getline (myfile2 , line) ) {
            string temp = "";
            for(int i = 0; i < line.length(); ++i) {
                if( line.substr(i,1).compare(" , ") != 0) {   // getting ' , ' then store it
                    temp += line[i];
                }
                else {
                    pattern.push_back(temp);
                    temp = "";
                    i = i + 2;
                }
                
            }
        }
        myfile2.close();
    }
    else {
        cout << "\nUnable to open pattern file\n";
    }
    if( check( text , pattern ) ) {
        cout<<"\nText contains Pattern\n";
    }
    else {
        cout<<"\nText does not contain Pattern\n";
    }
    return 0;
}