Get input from .txt

[nunks]

So me and my groupmates suddenly have some clutchwork at hand. I was assigned of making an import function that reads through a textfile that looks like this, and store it to a 2D array.
Like this
http://i.stack.imgur.com/abQ4a.png

The columns are Tab-separated however the difference from that image to mine is that i receive a 3x3 matrix with a blank space substituing one of the numbers and i was wondering how could i detect that blank space

[Stewbond]

there are a few options that you can use.

std::ifstream fin("input.txt");

std::string line;
std::getline(fin, line); reads to a new line

std::stringstream iss(line); // puts the line in a stream

std::getline(iss,cell,'\t'); // extracts a string which is tab delimited.

1) If you don't know the size of your data (3x3, 4x4, 5x3) then you want to either use dynamic memory (new/delete) or you want to use std::vector to store the data. Otherwise, if it's always 3x3 you are good with simply making an int[3][3] variable.
2) Whenever you read from the file, check the ifstream .good() function to ensure that you can continue reading from the file.
3) Use std::getline to delimit based on tabs. Use fin >> if you want to convert directly to a number if yoiu don't care about the white space and want to make it a number directly instead of astring first.

[nunks]

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

int main ()
{
	
std::ifstream fin("input.txt");

std::string line;
std::getline(fin, line); 

std::stringstream iss(line); // puts the line in a stream

std::getline(iss,3,'\t');
        
}

This gives me error :S
Nevertheless my .txt looks like this i.e

1 4 2
3 5
7 8 9

and i have to extract this to a 2d vector even the blank space and susbtitute it later by 0

[freddy92]

To use a stringstream you have to #include <sstream> (I think that's its name). Also since you're already using namespace std; there's really no reason to put std:: before everything.

[nunks]

it still gives me an error

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

void main ()
{
	
ifstream fin("example.txt");

string line;

getline(fin, line); 

stringstream iss(line); // puts the line in a stream

getline(iss,3,'\t');
        
}

[freddy92]

K, what error?

Edit: Why is your second parameter "3" in getline? the second parameter is the string that the chars will be stored in.

[nunks]

9 IntelliSense: no instance of overloaded function "getline" matches the argument list
argument types are: (std::stringstream, int, char) c:\Users\user\Desktop\ConsoleApplication4\ConsoleApplication4\Source1.cpp 18 1 ConsoleApplication4

[freddy92]

In case you didn't notice it, read my edit. That's your problem.

[nunks]

ok it works now but my matrix is separated by setw(5). is there any way to solve this?Its because im not using tab

[Smac89]

What do you mean by 'your matrix is seperated by setw(5)' ?

http://www.cplusplus.com/forum/beginner/96804/#msg520036

[nunks]

Like i have this in a txt

1 5 6
7 8
2 3 4

And all the elements are separeted by setw(5). What i really wanted was to get the values and get a 2d vector out of it subsituting the blank space for a zero in the vector

[Smac89]

Then use getc(FILE*). Your file has 3 lines and 3 cols; why are you using a 2d vector?

Use this get for c++
http://www.cplusplus.com/reference/istream/istream/get/

[nunks]

Thats because my game only accepts 2d vectors as a gameboard.
But how an i get getc to get those numbers and spaces and turn them i a 2d vector?