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function to read in data and create dynamic array of pointers

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Join Date: Nov 2008

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function to read in data and create dynamic array of pointers

Apr 13th, 2009

suppose the input file is...
5(number of cells)
1 2 -1 4
0 2 3 4
1 0 3 -1
2 -1 3 1
2 0 1 -1
how will i Write a function to read data from an input file to create a dynamic array of pointers to cells, create the required number of cells one by one, store their addresses at the corresponding index in the array. Then fill the data (given in the input file) in each cell.

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Re: function to read in data and create dynamic array of pointers

Apr 13th, 2009

It would be helpful to know what those numbers mean.

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Re: function to read in data and create dynamic array of pointers

Apr 13th, 2009

these are actually doors os a maze..
The four numbers indicate the cell numbers of the cells being led to through the respective door. -1 indicates absence of a door. For example, line number 2 is about cell number 0 and says that door 1 leads to cell 1, door 2 to cell 2, door 3 is absent, and door 4 leads to cell number 4.

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Re: function to read in data and create dynamic array of pointers

Apr 13th, 2009

If the first number is a cell number why are there duplicates ?

>>and says that door 1 leads to cell 1
There is no 1 on line 2. 0 2 3 4

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Re: function to read in data and create dynamic array of pointers

Apr 13th, 2009

its just an input format.......

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Re: function to read in data and create dynamic array of pointers

Apr 13th, 2009

So are you saying you just made up those numbers? You need to post some actual rows out of a real file.

The way I understand it, the first number is a cell number, second through fourth numbers are door numbers (three doors) and the value of the numbers indicate the cell number that the doors open to. If that is true then a cell is a square with only three doors, or only two doors when one of the door numbers is -1.

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Re: function to read in data and create dynamic array of pointers

Apr 13th, 2009

one more thing
whats the diffrence between
fin.get
and fin.getline??

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Re: function to read in data and create dynamic array of pointers

Apr 13th, 2009

getline() read an entire text line into the buffer. get() just read unformatted data, such as binary or text data.

There are two versions of getline() -- one for character arrays and the other for std::string.

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
std::string line;
char ln[255];
// character arrays
cin.getline( ln, sizeof(ln) );
//
// std::string
getline( cin, line );
std::string line;
char ln[255];
// character arrays
cin.getline( ln, sizeof(ln) );
//
// std::string
getline( cin, line );

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Re: function to read in data and create dynamic array of pointers

Apr 13th, 2009

thanks

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include<iostream>
#include<fstream>
using namespace std;
 
struct cell
{
	int *a[0];
	int *b[1];
	int *c[2];
	int *d[3];
	bool visited;
	int *back;
};
int main()
{
	int array[80];
	ifstream fin;
	ofstream fout;
	fin.open("input.txt");
	fout.open("output.txt");
	int num;
	while(!fin.eof())
	{
		fin>>num;
		for(int i=0; i<num; i++)
			fin.getline(array,80);
	}
	cout<<array;
	return 0;
}
#include<iostream>
#include<fstream>
using namespace std;

struct cell
{
	int *a[0];
	int *b[1];
	int *c[2];
	int *d[3];
	bool visited;
	int *back;
};
int main()
{
	int array[80];
	ifstream fin;
	ofstream fout;
	fin.open("input.txt");
	fout.open("output.txt");
	int num;
	while(!fin.eof())
	{
		fin>>num;
		for(int i=0; i<num; i++)
			fin.getline(array,80);
	}
	cout<<array;
	return 0;
}