I am trying to write a program that checks how many words are inside of other words. Then tell the user which word has the most words in it. For some reason, the while loop is breaking and I cannot get the file to reload. Any ideas?
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
struct finalWord {
string word;
int number;
};
ostream& operator<<(ostream& o, const finalWord& f) {
return o << f.word << ": " << f.number;
}
int main () {
finalWord f;
string line, holder, line2;
ifstream myFile("enable1.txt");
int counter;
int holdlen;
size_t found;
if (myFile.is_open()){
while(getline(myFile,line)){
holder = line;
while (getline(myFile, line)){
found = holder.find(line);
if (found != string::npos){
counter++;
}
if (counter > holdlen) {
f.word = line;
f.number = counter;
holdlen = counter;
}
counter = 0;
}
}
}
cout << f << endl;
}
Actually the problem you are facing is because of the two loops you are using with same myFile
IN First WHILE loop it will take a word
IN Second WHILE loop it will go through the rest of the file.
It will be an issue in the following case.
If a String "I am Happy" is occurred more than once then it will iterate for each occurrence to search up to end of the file.
So to avoid that you need to take the unique strings in an vector as said by Vaughn Cato and then do a check for the occurrence of that string in the whole file to make it efficient.
Related
i want to receive an input from user and search a file for that input. when i found a line that includes that specific word, i want to print it and get another input to change a part of that line based on second user input with third user input. (I'm writing a hospital management app and this is a part of project that patients and edit their document).
i completed 90 percent of the project but i don't know how to replace it. check out following code:
#include <iostream>
#include <stream>
#include <string.h>
#include <string>
using namespace std;
int main(){
string srch;
string line;
fstream Myfile;
string word, replacement, name;
int counter;
Myfile.open("Patientlist.txt", ios::in|ios::out);
cout << "\nEnter your Name: ";
cin.ignore();
getline(cin, srch);
if(Myfile.is_open())
{
while(getline(Myfile, line)){
if (line.find(srch) != string::npos){
cout << "\nYour details are: \n" << line << endl << "What do you want to change? *type it's word and then type the replacement!*" << endl;
cin >> word >> replacement;
}
// i want to change in here
}
}else
{
cout << "\nSearch Failed... Patient not found!" << endl;
}
Myfile.close();
}
for example my file contains this line ( David , ha , 2002 ) and user wants to change 2002 to 2003
You cannot replace the string directly in the file. You have to:
Write to a temporary file what you read & changed.
Rename the original one (or delete it if you are sure everything went fine).
Rename the temporary file to the original one.
Ideally, the rename part should be done in one step. For instance, you do not want to end up with no file because the original file was deleted but the temporary one was not renamed due to some error - see your OS documentation for this.
Here's an idea:
#include <iostream>
#include <fstream>
#include <string>
#include <cstdio>
using namespace std;
void replace(string& s, const string& old_str, const string& new_str)
{
for (size_t off = 0, found_idx = s.find(old_str, off); found_idx != string::npos; off += new_str.length(), found_idx = s.find(old_str, off))
s.replace(found_idx, old_str.length(), new_str);
}
int main()
{
const char* in_fn = "c:/temp/in.txt";
const char* bak_fn = "c:/temp/in.bak";
const char* tmp_fn = "c:/temp/tmp.txt";
const char* out_fn = "c:/temp/out.txt";
string old_str{ "2002" };
string new_str{ "2003" };
// read, rename, write
{
ifstream in{ in_fn };
if (!in)
return -1; // could not open
ofstream tmp{ tmp_fn };
if (!tmp)
return -2; // could not open
string line;
while (getline(in, line))
{
replace(line, old_str, new_str);
tmp << line << endl;
}
} // in & tmp are closed here
// this should be done in one step
{
remove(bak_fn);
rename(in_fn, bak_fn);
remove(out_fn);
rename(tmp_fn, in_fn);
remove(tmp_fn);
}
return 0;
}
One possible way:
Close the file after you read it into "line" variable, then:
std::replace(0, line.length(), "2002", "2003")
Then overwrite the old file.
Note that std::replace is different from string::replace!!
The header is supposed to be <fstream> rather than <stream>
you can't read and write to a file simultaneously so I have closed the file after reading before reopening the file for writing.
instead of updating text inside the file, your line can be updated and then written to file.
#include <iostream>
#include <fstream>
#include <string.h>
#include <string>
using namespace std;
int main(){
string srch;
string line, line2;
fstream Myfile;
string word, replacement, name;
int counter;
Myfile.open("Patientlist.txt", ios::in);
cout << "\nEnter your Name: ";
cin.ignore();
getline(cin, srch);
if(Myfile.is_open())
{
while(getline(Myfile, line)){
if (line.find(srch) != string::npos){
cout << "\nYour details are: \n" << line << endl << "What do you want to change? *type it's word and then type the replacement!*" << endl;
cin >> word >> replacement;
int index = line.find(word);
if (index != string::npos){
Myfile.close();
Myfile.open("Patientlist.txt", ios::out);
line.replace(index, word.length(), replacement);
Myfile.write(line.data(), line.size());
Myfile.close();
}
}
// i want to change in here
}
}else
{
cout << "\nSearch Failed... Patient not found!" << endl;
}
}
Here's the code that I based here http://www.thecrazyprogrammer.com/2015/02/c-program-count-occurrence-word-text-file.html. (new in c++)
#include <iostream>
#include <fstream>
#include<cstring>
using namespace std;
int main()
{
// std::cout << "Hello World!" << std::endl;
// return 0;
ifstream fin("my_data.txt"); //opening text file
int count=0;
char ch[20],c[20];
cout<<"Enter a word to count:";
gets(c);
while(fin)
{
fin>>ch;
if(strcmp(ch,c)==0)
count++;
}
cout<<"Occurrence="<<count<<"n";
fin.close(); //closing file
return 0;
}
Error in Patter Counting
my_data.txt has only 3 "world" in it, but as I run the program, it results to
here's the textfile's content
What could go wrong?
A solution using std::string
int count = 0;
std::string word_to_find, word_inside_file;
std::ifstream fin("my_data.txt");
std::cout << "Enter a word to count:";
std::cin >> word_to_find;
while (fin >> word_inside_file) {
if (word_to_find == word_inside_file )
count++;
}
std::cout << "Occurrence=" << count << "";
If you want to find all occurrences inside other strings as well, as mentioned in the comments, you can do something like this:
...
while (fin >> word_inside_file) {
count += findAllOccurrences(word_to_find, word_inside_file);
}
...
Inside findAllOccurrences(std::string, std::string) you will implement a "find all string occurrences inside another string" algorithm.
If you are new to c++ you shouldn't really use gets. Read about "buffer overflow vulnerability". gets() is more like c-style. You should consider using std::cin.
I need to parse a table of numbers formatted as ascii text. There are 36 space delimited signed integers per line of text and about 3000 lines in the file. The input file is generated by me in Matlab so I could modify the format. On the other hand, I also want to be able to parse the same file in VHDL and so ascii text is about the only format possible.
So far, I have a little program like this that can loop through all the lines of the input file. I just haven't found a way to get individual numbers out of the line. I am not a C++ purest. I would consider fscanf() but 36 numbers is a bit much for that. Please suggest practical ways to get numbers out of a text file.
int main()
{
string line;
ifstream myfile("CorrOut.dat");
if (!myfile.is_open())
cout << "Unable to open file";
else{
while (getline(myfile, line))
{
cout << line << '\n';
}
myfile.close();
}
return 0;
}
Use std::istringstream. Here is an example:
#include <sstream>
#include <string>
#include <fstream>
#include <iostream>
using namespace std;
int main()
{
string line;
istringstream strm;
int num;
ifstream ifs("YourData");
while (getline(ifs, line))
{
istringstream strm(line);
while ( strm >> num )
cout << num << " ";
cout << "\n";
}
}
Live Example
If you want to create a table, use a std::vector or other suitable container:
#include <sstream>
#include <string>
#include <fstream>
#include <iostream>
#include <vector>
using namespace std;
int main()
{
string line;
// our 2 dimensional table
vector<vector<int>> table;
istringstream strm;
int num;
ifstream ifs("YourData");
while (getline(ifs, line))
{
vector<int> vInt;
istringstream strm(line);
while ( strm >> num )
vInt.push_back(num);
table.push_back(vInt);
}
}
The table vector gets populated, row by row. Note we created an intermediate vector to store each row, and then that row gets added to the table.
Live Example
You can use a few different approaches, the one offered above is probable the quickest of them, however in case you have different delimitation characters you may consider one of the following solutions:
The first solution, read strings line by line. After that it use the find function in order to find the first position o the specific delimiter. It then removes the number read and continues till the delimiter is not found anymore.
You can customize the delimiter by modifying the delimiter variable value.
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
int main()
{
string line;
ifstream myfile("CorrOut.dat");
string delimiter = " ";
size_t pos = 0;
string token;
vector<vector<int>> data;
if (!myfile.is_open())
cout << "Unable to open file";
else {
while (getline(myfile, line))
{
vector<int> temp;
pos = 0;
while ((pos = line.find(delimiter)) != std::string::npos) {
token = line.substr(0, pos);
std::cout << token << std::endl;
line.erase(0, pos + delimiter.length());
temp.push_back(atoi(token.c_str()));
}
data.push_back(temp);
}
myfile.close();
}
return 0;
}
The second solution make use of regex and it doesn't care about the delimiter use, it will search and match any integers found in the string.
#include <iostream>
#include <string>
#include <regex> // The new library introduced in C++ 11
#include <fstream>
using namespace std;
int main()
{
string line;
ifstream myfile("CorrOut.dat");
std::smatch m;
std::regex e("[-+]?\\d+");
vector<vector<int>> data;
if (!myfile.is_open())
cout << "Unable to open file";
else {
while (getline(myfile, line))
{
vector<int> temp;
while (regex_search(line, m, e)) {
for (auto x : m) {
std::cout << x.str() << " ";
temp.push_back(atoi(x.str().c_str()));
}
std::cout << std::endl;
line = m.suffix().str();
}
data.push_back(temp);
}
myfile.close();
}
return 0;
}
I have a problem trying to count words inside of a vector. A vector holds every line from a file as an object. v[0] is the first line, v[1] is the second line, so on.
For my countWords() function, it only works for counting v[0]. Any object past that is ignored or missed some how. Any ideas? Thanks in advance.
#include <cstdlib>
#include <fstream>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
int countWords(vector<string> v)
{
stringstream ss;
string word;
int count = 0;
for(int i = 0; i < v.size(); i++) {
ss.str(v[i]);
while (ss >> word)
count++;
}
return count;
}
void readFile(string filename,vector<string> &v)
{
fstream file;
string line;
file.open(filename,ios::in);
while(getline(file,line)) { //Reads the file line by line ...
if(line == "") //... ignoring any empty lines ...
continue;
v.push_back(line); //... and puts them into our vector.
}
file.close();
}
int main(int argc,char* argv[])
{
if (argc != 2) { //Terminate unless the user enters -ONE- entry.
cout << "Usage: " << argv[0] << " <filename>" << endl;
exit(1);
}
string filename = argv[1];
vector<string> fileContents;
readFile(filename,fileContents);
cout << countWords(fileContents) << endl;
}
As an alternative to RichieHindle's answer, this works too. Just have the stringstream scope local to the for loop and it will reset properly.
int countWords(vector<string> v)
{
string word;
int count = 0;
for(int i = 0; i < v.size(); i++) {
stringstream ss(v[i]);
while (ss >> word)
count++;
}
return count;
}
Before you reuse stringstream you must do
ss.clear();
after your while loop.
You could also declare it inside the for() loop, but then it would be reinitialized again. For readabillity, this might be better. Performancewise it could make a difference.
I bet ss goes into an error state when you've exhausted it for the first time and doesn't reset just because you call str.
Declare ss inside the for loop and pass the string directly to the constructor. This avoids such problems.
In general, you have the bad habit of declaring your variables in a bunch instead of closest to where you need them, and not using constructors. For example, you could pass the filename to fstream's constructor instead of calling open. And you could use ifstream so you don't need the second argument.
I need to read in a text file of 500 words or more(a real world article from newspaper, etc..) and locate and tag like this, <location> word <location/>, and then print the entire article on the screen. Im using boost regex right now and its working ok. I want to try and use a list or array or some other data structure to have a list of the states and major cities, and search those and compare to the aticle. right now I'm using an array but I'm willing to use anything. Any ideas or clues?
#include <boost/regex.hpp>
#include <iostream>
#include <string>
#include <boost/iostreams/filter/regex.hpp>
#include <fstream>
using namespace std;
int main()
{
string cities[389];
string states [60];
string filename, line,city,state;
ifstream file,cityfile, statefile;
int i=0;
int j=0;
cityfile.open("c:\\cities.txt");
while (!cityfile.eof())
{
getline(cityfile,city);
cities[i]=city;
i++;
//for (int i=0;i<500;i++)
//file>>cities[i];
}
cityfile.close();
statefile.open("c:\\states.txt");
while (!statefile.eof())
{
getline(statefile,state);
states[j]=state;
//for (int i=0;i<500;i++)
//cout<<states[j];
j++;
}
statefile.close();
//4cout<<cities[4];
cout<<"Please enter the path and file name "<<endl;
cin>>filename;
file.open(filename);
while (!file.eof())
{
while(getline(file, line)
{
}
while(getline(file, line))
{
//string text = "Hello world";
boost::regex re("[A-Z/]\.[A-Z\]\.|[A-Z/].*[:space:][A-Z/]|C........a");
//boost::regex re(
string fmt = "<locations>$&<locations\>";
if(boost::regex_search(line, re))
{
string result = boost::regex_replace(line, re, fmt);
cout << result << endl;
}
/*else
{
cout << "Found Nothing" << endl;
}*/
}
}
file.close();
cin.get(),cin.get();
return 0;
}
If you are after asymptotic complexity - Aho-Corasick algorithm offers a linear time complexity ( O(n+m)) (n and m are the lengths of the input strings). for searching a dictionary in a string.
An alternative is to put the tokenized words in a map (where the value is a list to the places in the stream of each string), and search for each string in the data in the tree. The complexity will be O(|S| * (nlogn + mlogn) ) (m being the number of searched words, n is the number of words in the string, and |S| is the length of the average word)
You can use any container that has a .find() method or supports std::find(). I'd use set, since set::find() runs in less than linear time.
Here is a program which does what you talk about. Note that the parsing doesn't work great, but that's not what I'm trying to demonstrate. You could continue to find the words using your parser, and use the call to set::find() to determine if they are locations.
#include <set>
#include <string>
#include <iostream>
#include <sstream>
const std::set<std::string> locations { "Springfield", "Illinois", "Pennsylvania" };
int main () {
std::string line;
while(std::getline(std::cin, line)) {
std::istringstream iss(line);
std::string word;
while(iss >> word) {
if(locations.find(word) == locations.end())
std::cout << word << " ";
else
std::cout << "<location>" << word << "</location> ";
}
std::cout << "\n";
}
}