Question

in c++ please. Write a program that reads the contents of a text file. The program should create a map in which the keys are the individual words found in the file and the values are the number of times each word appears. For example, if the word "the" appears 128 times, the map would contain an element with "the" as the key and 128 as the value. The program should either display the frequency of each word or create a second file containing a list of each word and its frequency.

Answer 1

//program ReadFreq.cpp

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#include<fstream> //this is for read and write into file

#include<iostream> //this is for read and write from user

#include<string> //this is for string operation

#include<map> //using map stl library

#include<iterator> //using iterator

using namespace std;

//prototype of writeFreq function to write data to file

void writeFreq(string, ofstream &);

int main()

{

//read word by word from file into this word

string word;

//make an input file reader pointer

ifstream in;

//make an output file writer pointer

ofstream out;

//map to store freq of word

map<string,int> freq;

//open input file for reading

in.open("input.txt");

//open output file for writing

out.open("output.txt");

//using while loop read complete file word by word

while(in >> word){

//if word already in map just increase it value by 1

if(freq.count(word)>0){

freq.insert(pair<string,int>(word,freq[word]++));

}else{

//for new word make in value as 1

freq.insert(pair<string,int>(word,1));

}

}

//make an iterator for map

map<string,int>::iterator itr;

//using for loop on the map using iterator and print it to the screen and write to the file

for(itr = freq.begin(); itr != freq.end(); itr++){

string output = "";

output += itr->first + " : " ;

output += to_string(itr->second) + "\n";

writeFreq(output,out);

cout<<output;

}

//close both the files

in.close();

out.close();

return 0;

}

//This is the final method which write the freq and the word to the file

void writeFreq(string output, ofstream& out){

out<<output;

}

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input.txt

this is the demo file and this is for demo purpose only.

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output

vikash@vikash: /media/vikash/New Volume/LAB/ HomeworkLib/october/18$ g++ ReadFreq.cpp vikash@vikash:/media/vikash/New Volume/LAB/HomeworkLib/october/18$ ./a.out and : 1 demo : 2 file : 1 for : 1 is : 2 only. :1 purpose : 1 the : 1 this : 2 vikash@vikash:/media/vikash/New Volume/LAB/HomeworkLib/october/18$

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output.txt