C++ :: Using Istringstream To Read Each Word Of Each Element In Vector

Mar 6, 2014

Consider I have a vector of strings and then I use an istringstream to read each word of each element in the vector, why do I nescessarily use an istringstream?

This is the code that does what I just described (I think)..

Code:
for(auto &elem : svec) {
istringstream strm(elem);
while (strm >> word)
//Magic
}

What would be the equivalent of using something else than an istringstream in this scenario and how does the istringstream work?

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C++ :: Converting Int To String Using Istringstream Inserts Commas

Jan 23, 2014

So I have a following function that converts int to string however it inserts the commas for thousands, millions, and so on. e.g. 65432 -> "65,432".

How do I make the conversion but have a string without commas?

I know it has to with locale but I cannot find it how to prevent it. Also I know about std::stoi() and atoi() but I do not want them.

Code:
template <typename T>
std::string NumberToString ( T Number ) {
std::stringstream ss;
ss << Number;
return ss.str();
}

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C++ :: How To Insert Element Into A Vector At Particular Index

May 3, 2013

I am storing info in a vector but I want to store certain info at a particular index. I am new to using vectors and am unsure about have to do this. I am aware of the insert method but am confused on how to use it to store at a particular index.

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C++ :: Pop Element On A Vector Off And Return Its Value At Same Time

Sep 6, 2014

I am trying to pop the element on a vector off and return its value at the same time

vector.push_back();

Unfortunately that code only removes that element from the vector it does not return it

Is the only way to get the element and destroy it is to do this?

vector.back();
vector.pop_back();

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C++ :: How To Access Element Of Point3f Vector

Aug 4, 2013

How to access an element of the point3f vector. E.g. :

int main() {
vector<Point3f> a;
a.push_back(Point3f(0,0,0);
a.push_back(Point3f(0,0,1);

//print first x,y,z element
cout<<a[0]<<endl;

[Code] ...

But it doesn't work firstly because it says can't use typename i.e. <float>

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C++ :: How To Remove Element Of A Vector And Returning It

Sep 22, 2014

pop_back just returns void, so I just can't use that?

erase is okay but it doesn't return anything....

Do I use a combination of both?

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C++ :: Search A Vector Element With Multiple Strings?

Nov 22, 2013

How could I search a vector element with multiple strings

i.e. vector.at(i) = This is a test

How could I search that to look for the word "test" in that element?

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C++ :: Changing Class Type Of A Vector Element?

Aug 16, 2014

I am programming a 2-D platformer video game. The stages are composed of an array (really a vector) of 16x16 px^2 tiles. I have defined a base class "Tile" and several derived classes, e.g., "Ramp", "Door", etc., which have their own attributes. The idea is that upon entering a room, the program will load all of the necessary tile data for that room into a vector. So, I have a vector that looks like: vector <Tile*> room_tiles, and resize it based on the total number of tiles in the room: room_tiles.resize(Tile_Count). I then want to read in certain info from the data file containing all of the tile information for that room. For example, if the data file says Tile 5 should be a ramp, I want to change the 5th element of the room_tiles vector to the derived ramp class. This is really where I'm having trouble. I've worked with vectors of base and derived classes before, but those were always of indeterminate size and I always used something like: (Vector).push_back(new DerivedClass()) to specify the derived class of that element. The problem is that that method only seems to work if you are appending elements to the end of a vector.

how I can do this?

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C++ :: Open File And Read In Rows To String Vector And Return Vector

Jun 7, 2012

I have a cpp app that reads in a number of files and writes revised output. The app doesn't seem to be able to open a file with a ' in the file name, such as,

N,N'-dimethylethylenediamine.mol

This is the function that opens the file :

Code:
// opens mol file, reads in rows to string vector and returns vector
vector<string> get_mol_file(string& filePath) {
vector<string> mol_file;
string new_mol_line;
// create an input stream and open the mol file
ifstream read_mol_input;
read_mol_input.open( filePath.c_str() );

[Code] ....

The path to the file is passed as a cpp string and the c version is used to open the file. Do I need to handle this as a special case? It is possible that there could be " as well, parenthesis, etc.

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C++ :: Filling Vector From A File - Adding Empty Element At The End

Apr 20, 2014

I'm having a problem filling a vector from a file. Basically, it is adding an empty element at the end. I'm new to Qt and haven't worked with file streams much so how to stop the stream before it adds the extra element.

void gui::get_data() {
mileage.clear();
QFile file(file_label->text() + ".txt");
QTextStream in(& file);
float m;
float g;
QString d;

[Code] ....

But, if I add another element to the vector and write that the file look like this.

//file after adding element
132654 0 02132014
132654 0 02132014
0 0
132998 22 02202014

I have it set to append at the moment so that is why the first line is repeated. I figure the problem is with if(in.atEnd()). I could fix it by deleting the last element right after adding it, but that seems like more of a hack than anything else.

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C++ :: Sequentially Remove One Element From Vector At A Time With Replacement?

Dec 8, 2014

I have a vector of int,

Code:
vector<int> row_numbers{1,2,3,4,5,6,7,8,9};

I want to sequentially remove one element at a time starting with the first. When the second element is removed, the first element needs to go back in. The sequence would look like

Code:
// original vector, row_numbers.size()=9
row_numbers{1,2,3,4,5,6,7,8,9};
// trimmed vector, row_numbers_trim.size()=8

[Code] .......

I have been working under the assumption that the best method would be to have row_numbers remain untouched and work on a copy. For each step in the sequence, you would create row_numbers_trim as a copy of row_numbers, and then remove an element from row_numbers_trim.

Code:
// position being removed
int counter = 0;
// copy original vector
row_numbers_trim = row_numbers;
// remove the first element from the copy
row_numbers_trim(row_numbers_trim.begin()+counter);

All you would have to do here is to increment counter in a loop. is there a better way?

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Visual C++ :: Selecting 1 Element From Each Vector Without Duplication Of Any Combination

Jul 15, 2013

I have N vectors which look like this:

[1→m] [m+1→2m] [2m+1→3m] [3m+1→4m] [4m+1→5m]..... [{(N-1)m}+1→Nm]

I want to select 1 element from each vector without duplication of any combinations. Essentially only when all combinations are done with 1st element in first vector ,only then it should move to next element in first vector.

Say i have elements :[123] [456] [789]

my combinations should be like
147
148
149
157
158
159
167
168
169
247....

Also, I cant have any repetitions and only after all combinations of 1 are done only then the loop has to move to next combination ie 247 combination and so on.

I tried NCK (n choose k) command but it gave me random combinations. How should i go about it with using minimal for loops?

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C :: Shared Memory / Cannot Read Last Element In A Struct

Jun 27, 2014

I have trouble reading the last element in a struct.I do get the correct value for the first two elements. In my example that is:

a = 11 and c = H
however I get:
b = 0
but I am expecting b=2

I got two files to handle this.The first one is writing data to memory -

Code:

#include <sys/shm.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
}

[code]....

why I cannot get correct value for the third element in my struct?In the second file where I'm reading from memory I allocate some space. Is this incorrect in some way? I'm running this on a Linux machine.

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C/C++ :: Change Each Word In Vector To Uppercase?

May 3, 2014

What I am trying to do is read a sequence of words from cin and store the values on a vector. Then process the vector and change each word to uppercase.

I know line 21 is the problem. I think I don't have the right syntax. That syntax works on string. I'm trying to adapt and use it on vector but it doesn't work.

#include <iostream>
#include <string>
#include <vector>
int main()

[Code]....

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C/C++ :: Word Maze - Find String In Vector

Mar 4, 2015

This program is to solve a word maze and find the number of words in the maze from a dictionary file.

The program runs, but stops by finding 1,2 and 3 letter words.

#include<iostream>
#include<vector>
#include<fstream>
#include<algorithm>
#include<string>
using namespace std;
int main() {
vector <string> dict,forward,reverse;

[Code] .....

I also tried to find words using the entire vector as a container, the synopsis code that also did not work is below

while(j<dict.size()) {
if(dict[j].size()>2) {
if (std::find(forward.begin(), forward.end(), dict[j]) != forward.end()) {
cout<<"found word "<<dict[j]<<endl;

[Code] ....

Attached File(s)

dumpling2.txt (2.54K)

Dictionary.txt (718.34K)

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C++ :: Read Word Then Add To List

Jun 4, 2013

So I'm trying to complete this part of a program where I have to read a text file from Stdin and add it to the 'word list' wl. I get how to read from a text file but I don't know how to go about adding 'words' to a list, if that makes sense. So here's what I got:

string getWord(){
string word;
while (cin >> word){
getline(cin, word);
} return word;

[Code] .....

Source is an array that determines how many words are read from the text and length is the amount printed on screen. Here's the program I'm writing the implementation for:

#include <iostream>
#include <string>
#include <vector>
#include "ngrams.h"

[Code] ....

I'm supposed to use this as a reference.

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C++ :: How To Read A Specific Word From A File

Aug 12, 2014

How would one go about doing this? I am very fond with Windows I/O, but not so much with this subject. I am decent with fstream, probably not as skilled at it as I should be, but I assume <fstream> would be a better choice, since it isn't locked to Windows.

Anyway, say I have a .txt file like this:

Bill is a cow.
Bill likes meat.
Bob is a pig.
Bob and Bill are friends.

And I want to count the number of times "Bill" is written. How would I do that?

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C++ :: How To Read A String And Then Compare It To A Word

Mar 5, 2014

I'm trying to read a string and then compare it to a word.

My code:

char* cmd = "start";
std::cin >> cmd;
if (strcmp (cmd, "eval"))
eval ();

When the program gets to the cin part, it breaks.

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C :: Read In N / Then N Words And Check To See If First Word Is Repeated

Sep 23, 2013

Read in n, then n lastnames, and check to see if the first in the list is ever repeated again.Here's what I have so far:

Code:

#include <stdio.h>
#include <stdlib.h>
int strcmp(char *w1, char *w2);
int main() {
int j, n;
char string1[30], string2[30];
}

[code]....

I see the problem is that it lies within n amount of string that I am not going through every string to compare to the first one.How will do compare every string to the first one?

Current output:
3
alex
alex
alex
Not repeated

3
alex
ash
peter
Not repeated

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C++ :: Making A Program Read A Word In Backwards / Reverse?

Feb 26, 2014

Lets say I have my name "Kevin".

What would the program be so it reads "niveK"?

How to write the program for that?

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Visual C++ :: Error When Trying To Read A Random Word From A File

May 8, 2015

I am currently writing a password generator in Microsoft Visual Studios 2010 Professional. The section I am having a problem with is the practical password. It is suppose to randomly read 3 words from a text file and then display it in the text box. The program will compile and run but when I hit generate I get "True True True" and not three random words. Then this warning shows up:

Warning C4800: 'char *' : forcing value to bool 'true' or 'false' (performance warning)

//Code is from the form1.h file. I can post the rest of the code if need be but I just included my includes and the problematic section

Code:
#pragma once
#include <cstdlib>
#include <ctime>
#include <stdlib.h>
#include <cmath>
#include <iostream>
#include <iomanip>

[Code] ....

Screenshot of the warnings: [URL] .....

Picture of the output: [URL] ....

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C++ :: Can't Read In Matrix Into Vector Of Vector Of Int

Mar 24, 2012

Code:
#include <iostream>
#include <istream>
#include <fstream>
#include <vector>

[Code]....

Why is it reading in nothing for the arrays, and also making the size of the total thing the total number of numbers? It should have a size of 2, not 5.

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C++ :: Read Multiple Text Files And Count Occurrences Of Word

Jun 8, 2013

I am supposed to read(scan) data from a folder with multiple(21578) text files, and file names are numbered from 1 to 21578,and read each word that occurs in a text file, and count the number of times it occurs in the entire folder,i.e; in all the files how do i go about it? I've tried this so far..but it isn't working..

#include <iostream>
#include <map>
#include <string>
using namespace std;
void incrementString(map<string, int> &theMap, string &theString) {
if(theMap.count(theString)) {

[Code] ....

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C++ :: For Loop In Hangman Game - Read A Word From Text File Randomly And Matches It With Definition

Jun 26, 2014

Ok here I have a program that reads a word from a text file randomly and matches it with the definition. The user has to guess what the word is according to the definition.

I'm having trouble with my for loop, I'm not getting any errors. But I just know something is off.

Here's my code:

#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>
#include <ctime>

using namespace std;
int main(){
int number;
int count = 0;
int numOfGuess = 0;

[Code] ...

This is words.txt:

apple#the usually round, red or yellow, edible fruit of a small tree
boat#a vessel for transport by water
horse#a solid-hoofed plant-eating domesticated mammal with a flowing mane and tail, used for riding
television#a system for transmitting visual images and sound that are reproduced on screens
soup#a liquid dish, typically made by boiling meat, fish, or vegetables, etc.
bottle#a container, typically made of glass or plastic and with a narrow neck
barber#a person who cuts hair
toast#sliced bread browned on both sides by exposure to radiant heat
radar#a system for detecting the presence, direction, distance, and speed of aircraft, ships, and other objects
red#of a color at the end of the spectrum next to orange and opposite violet

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C++ :: Read Story From Input File / Separate Words And Output Lines On Which The Word Occurs

Feb 21, 2014

I have program that is supposed to read in a story from an input file and separate the words and output the lines on which the word occurs. It needs to read in another input file that has a list of words (1 per line) to ignore. i.e. skip them when running through the story. This is what I have so far, I've changed multiple things trying to get it running....

#include<iostream>
#include<fstream>
#include<map>
#include<set>
#include<vector>
#include<string>
#include"split.h"

[Code] .....

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C++ :: Linked List - Function Which Deletes Element If Next Element Is Bigger

Mar 10, 2014

So I have linked list and function which deletes element if next element is bigger, so my code is working but its not working with first element, in the comment I have wrote code which I would code for checking that first element, but when ever I check it is blowing up all program.

#include <iostream>
using namespace std;
struct llist {
int x;
llist *next;

[Code] .....

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