Help with two dimensional arrays

[uchi240]

I'm not sure if I'm reading too much into it. But I'm trying to make a 5x5 two dimensional array count as such.

1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25

without using

 
ar[5][5] = {1, 2, 3, 4, 5}{6, 7, 8, 9, 10}etc...

This is how I'm trying to write my code...

#include <iostream>

using namespace std;

void fill(int ar[][5], int size);
void print(int ar[][5], int size);

int main()
{
	int ar[5][5];

	fill(ar, 5);
	print(ar, 5);

	return 0;
}
void fill(int ar[][5], int size)
{
	for (int row = 1; row < size; row++)
	{
		for (int col = 0; col < size; col++)
		{
			ar[row][col] = row + col;
		}
	}
}
void print(int ar[][5], int size)
{
	for (int row = 1; row < size; row++)
	{
		for (int col = 0; col < size; col++)
		{
			cout << ar[row][col] << '\t';
		}
		cout << endl;
	}
}

Am I over thinking it? Please someone help. Thank you also

[alfredokang]

No...Its good you are learning more...Keep on

[uchi240]

Ok... So, I was thinking that I can increment the for loops differently. But, whenever I do, it won't output the 5x5 two dimensional array anymore. It outputs something like

1 4
2 5
3 6
4 7
5 8

Why is it doing that?

[uchi240]

Not gonna lie... I've been stuck on this for four hours. I'm probably just talking to myself. Haha. But, here it is. I finally got it.

#include <iostream>

using namespace std;

void fill(int ar[][5], int size);
void print(int ar[][5], int size);

int main()
{
	int ar[5][5];

	fill(ar, 5);
	print(ar, 5);

	return 0;
}
void fill(int ar[][5], int size)
{
	for (int i = 1; i < 20; i += 5)
	{
		for (int j = 0; j < size; j++)
		{
			ar[i][j] = i + j;
		}
	}
}
void print(int ar[][5], int size)
{
	for (int i = 1; i < 20; i += 5)
	{
		for (int j = 0; j < size; j++)
		{
			cout << ar[i][j] << '\t';
		}
		cout << endl;
	}
}

Thanks alfredokang for the encouragement.

[JLBorges]

#include <iostream>
#include <iomanip>
#include <numeric>
#include <iterator>

const int COLS = 5 ; 
void fill( int ar[][COLS], int size )
{
    int n = 0 ;
    for( int i = 0 ; i < size ; ++i )
        for( int j = 0 ; j < COLS ; ++j ) ar[i][j] = ++n ;
}

void print( const int ar[][COLS], int size )
{
    for( int i = 0 ; i < size ; ++i )
    {
        for( int j = 0 ; j < COLS ; ++j ) 
            std::cout << std::setw(3) << ar[i][j] << ' ' ;
            
        std::cout << '\n' ;
    }
}

int main()
{
    {
        int a[5][COLS] ;
        fill( a, 5 ) ;
        print( a, 5 ) ;
    }
    std::cout << "-------\n" ;
    
    {
        int b[5][COLS] ;
        int n = 0 ;
        for( auto& row : b ) for( int& i : row ) i = ++n ;
        for( const auto& row : b ) 
        { 
            for( int i : row ) std::cout << std::setw(3) << i << ' ' ;
            std::cout << '\n' ;
        }
    }
    std::cout << "-------\n" ;
    
    {
        int c[5][COLS] ;
        std::iota( std::begin( c[0] ), std::end( c[COLS-1] ), 1 ) ;
        for( const auto& row : c ) 
        { 
            for( int i : row ) std::cout << std::setw(3) << i << ' ' ;
            std::cout << '\n' ;
        }
    }
    std::cout << "-------\n" ;
}

http://coliru.stacked-crooked.com/a/17c9486bc8b54df3

[chofs]

hope the following code helps....its from a text file if you infile....only works for square matrixs

 
#include <iostream>
#include <vector>
#include <fstream>
#include <cmath>

using namespace std;
void matrix(vector<int>&data)
{
    int arr1[10][10];
    int result[10][10];

    ifstream infile("input.txt");
    int d=0;
    //////////////////////////////infiling
    while(infile>>d)
    {
        data.push_back(d);
    }
    int counter=0;
    int asize=sqrt(data.size());

    ///////////////////////////////////storing results in 2d array;
    for(int i=0;i<asize;i++)
    {
        for(int j=0;j<asize;j++)
        {
            arr1[i][j]=data.at(counter);
            counter++;
        }

    }
    ////////////////////////////////////diaplaying
    for(int i=0;i<asize;i++)
    {
        for(int j=0;j<asize;j++)
        {
            cout<<arr1[i][j]<<"  ";

        }
        cout<<endl;

    }

}

int main()
{
    vector<int>data;
    matrix(data);
    return 0;
}