Expiring Today—Celebrate National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

number of occurences of a specific text in a file using c++

Posted on 2011-03-08
2
Medium Priority
?
282 Views
Last Modified: 2012-05-11
Hi,

I have a huge text file. I would like to know, for example, how many times "Mumbai" is present in the file. Can anyone suggest a quick, efficient way of doing this using c++, STL etc? Thanks in advance.

0
Comment
Question by:mumbaikar
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 5

Accepted Solution

by:
TomasP earned 1000 total points
ID: 35369632
From the site
http://www.cplusplus.com/reference/string/string/find/// string::find
First load the file into a string
Then put the the find logic below in a loop and every time you find "Mumbai" increment a counter
Make sure you increment found by 1 so the search doesn't find the same "Mumbai" repeatedly but rather searches the whole string

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

int main ()
{
  string str ("There are two needles in this haystack with needles.");
  string str2 ("needle");
  size_t found;

  // different member versions of find in the same order as above:
  found=str.find(str2);
  if (found!=string::npos)
    cout << "first 'needle' found at: " << int(found) << endl;

  found=str.find("needles are small",found+1,6);
 if (found!=string::npos)
    cout << "second 'needle' found at: " << int(found) << endl;

  found=str.find("haystack");
  if (found!=string::npos)
    cout << "'haystack' also found at: " << int(found) << endl;

  found=str.find('.');
  if (found!=string::npos)
    cout << "Period found at: " << int(found) << endl;

  // let's replace the first needle:
  str.replace(str.find(str2),str2.length(),"preposition");
  cout << str << endl;

  return 0;
0
 

Author Closing Comment

by:mumbaikar
ID: 35372055
Thanks. This was a great help.
0

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

The following diagram presents a diamond class hierarchy: As depicted, diamond inheritance denotes when two classes (e.g., CDerived1 and CDerived2), separately extending a common base class (e.g., CBase), are sub classed simultaneously by a fourt…
In Easy String Encryption Using CryptoAPI in C++ (http://www.experts-exchange.com/viewArticle.jsp?aid=1193) I described how to encrypt text and recommended that the encrypted text be stored as a series of hexadecimal digits -- because cyphertext may…
Video by: ITPro.TV
In this episode Don builds upon the troubleshooting techniques by demonstrating how to properly monitor a vSphere deployment to detect problems before they occur. He begins the show using tools found within the vSphere suite as ends the show demonst…
In this video, Percona Director of Solution Engineering Jon Tobin discusses the function and features of Percona Server for MongoDB. How Percona can help Percona can help you determine if Percona Server for MongoDB is the right solution for …

718 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question