Data input

[Furjoza]

Hi,
I have to write a program where my input data will be "send" like this:
5
2 43 5 54 5
3 54 5 34
43 4 12
32 3
6
The first numbers says how many rows there will be. So I decided to create tables/vectors for each row. The problem is that I dont really know how to read data separated with space/whitespace and how to determine is it was divided by end of line sing or the space. Please help me ;)

[MiiNiPaa]

How to read single line and sum all whitespace delimited values:

#include <sstream>
//...
std::string temp;
std::getline(std::cin, temp); //Read whole string
std::istringstream line(temp); //Create input stream from string we read before
int i, sum = 0;
while(line >> i) //Read values until the end of line;
    sum +=i;
std::cout << i;

[Furjoza]

std::string temp;
std::getline(std::cin, temp); //Read whole string
std::istringstream line(temp); //Create input stream from string we read before
int i, x, y;
cin >> y;
int* table = new int[y][y];
for(int z = 0; z <= y; z++)
{
 x=0;
 while(line >> i) //Read values until the end of line;
 {
  Table[x][z]=i;
  x++;
 }
}

Will it save my whole data in the table?

[MiiNiPaa]

Nope, you are reading only single line.
My code shows how to read one line. Loop it over to read several lines.

[Furjoza]

int main()
{
	int i, x, y;
	cin >> y;
	int* table = new int[y][y];
	//for(int z = 0; z <= y; z++)
	//{
		std::string temp;
		while(std::getline(std::cin, temp)) //Read whole string
		{
			std::istringstream line(temp); //Create input stream from string we read before
			x=0;
			while(line >> i) //Read values until the end of line;
			{
				Table[x][z]=i;
				x++;
			}
		}
	//}
}

Now it works?

[MiiNiPaa]

Why don't you check it out :)
I would suggest you to use vectors if your table has different length rows.

Example code using C++11:

#include <sstream>
#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
#include <limits>


int main() {
    int rows;
    std::cin >> rows;
    std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
    std::vector<std::vector<int>> table(rows);
    for(int i = 0; i < rows; ++i) {
        std::string temp;
        std::getline(std::cin, temp);
        std::istringstream line(temp);
        std::copy(std::istream_iterator<int>(line),
                  std::istream_iterator<int>(),
                  std::back_inserter(table[i]));
    }
    for(const auto& v: table) {
        for(int i: v)
            std::cout << i << ' ';
        std::cout << '\n';
    }
}

http://ideone.com/2rlWHK

[Furjoza]

I dont understand line 12 and (18,23) :(

[MiiNiPaa]

line 12

http://stackoverflow.com/questions/5131647/why-would-we-call-cin-clear-and-cin-ignore-after-reading-input

(18,23)

It is just a replacement for loop:

{
    int tmp;
    while(line >> tmp)
        table[i].push_back(tmp);
}

You can use that instead of that line.
http://www.cplusplus.com/reference/algorithm/copy/
http://www.cplusplus.com/reference/iterator/istream_iterator/
http://www.cplusplus.com/reference/iterator/back_inserter/

[Furjoza]

Thanks ;) Just last question. How to make it work?

		long long** table = new long long*[n];
		for( int i = 0; i < n; i++ )
		{
			table[i] = new long table[4];
		}

error C2440: '=' : cannot convert from 'long *' to '__int64 *'
What im trying to do is 2 demensional array with dynamic 'n' and constant [4]. Somethink like long long table[n][4]
EDIT:
I made it look like that:

		long long **table = new long long*[n];
		for( int i = 0; i < n; i++ )
		{
			table[i] = new long long[4];
		}

Not sure if working still testing.

[MiiNiPaa]

Some inconsistency:

long long** table
//...
new long table

[Furjoza]

My first dynamic array! :D I have final question I think :) Can you help me to transform this:

#include "stdafx.h"
#include <iostream>
#include <sstream>
int main()
{
	int t;
	std::cin >> t;
	for ( int x = 0; x < t; ++x )
	{
		long n;
		std::cin >> n;
		long long **table = new long long*[n];//Nie małe tworzenie tablicy
		for( int i = 0; i < n; i++ )
		{
			table[i] = new long long[4];
		}
		std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
		for( int y = 0; y < n; y++ )
		{
			std::string temp;
			std::getline(std::cin, temp);
			std::istringstream line(temp);
			for( int v=0; v < 4; v++ ) 
			{
				line >> table[y][v];
			}
			std::cout << table[y][0] << " " << table[y][1] << " " << table[y][2] << " " << table[y][3];
		}
	}
	std::cin.get();
}

I guess its working! Thanks for your help ;)
EDIT:
I had to change std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
into
std::cin.ignore(); and its working :D

[Codermik]

1 important thing, you have a memory leak - you are not freeing the memory allocated for your 2D array.

[j3Rz8vqX]

	//Free memory:
	for( int i = 0; i < n; i++ )
	{
		delete []table[i];//deletes 'n' embedded arrays
	}
	delete []table;//deletes outer array