How to eliminate some items in a for loop

[PressClass]

The code below will output

1.1, 1.2, 1.3, 1.4, 1.5,
2.1, 2.2, 2.3, 2.4, 2.5,
3.1, 3.2, 3.3, 3.4, 3.5,
4.1, 4.2, 4.3, 4.4, 4.5,
5.1, 5.2, 5.3, 5.4, 5.5,

  #include <iostream>
using namespace std;

int main ()


{

	int n = 0;
	int m = 1;  
	for (int i = 0; i < 5; i++ )
	{	
		for (int e = 0; e < 5; e++ )
		{	
			cout << m << "." << ++n <<  ", ";  
		}
			n = 0;
			m = m + 1;
			cout << endl;
	}  
}
.

I want it to show the numbers in a way that the next number should not be equal or bigger than the one before.

in other words, the output should be:

1.2, 1.3, 1.4, 1.5
2.3, 2.4, 2.5
3.4, 3.5
4.5

I hope someone helps me. I did not do programming for a long time. I want to come back.

[deleted account xyzzy]

#include <iostream>

int main()
{
   const int max_num { 5 };

   for ( int i { 1 }; i <= max_num; ++i )
   {
      for ( int j { i }; j <= max_num; ++j )
      {
         if ( j == i ) continue;

         std::cout << i << '.' << j;

         if ( j != max_num ) std::cout << ", ";
      }

      std::cout << '\n';
   }
}

http://coliru.stacked-crooked.com/a/879d95e1a01aa852

[deleted account xyzzy]

I want it to show the numbers in a way that the next number should not be equal or bigger than the one before.

I believe you want the next number to not be smaller or equal, that is what your desired output shows.

[deleted account xyzzy]

An even more compact version:

#include <iostream>

int main()
{
   const int max_num { 5 };

   for ( int i { 1 }; i <= max_num; ++i )
   {
      for ( int j { i + 1 }; j <= max_num; ++j )
      {
         std::cout << i << '.' << j;

         if ( j != max_num ) std::cout << ", ";
      }

      std::cout << '\n';
   }
}

http://coliru.stacked-crooked.com/a/43349676143df5bd

[keskiverto]

A different look at the goal:

1.2, 1.3, 1.4, 1.5
2.3, 2.4, 2.5
3.4, 3.5
4.5

Lets add metadata:

row=1 1.2, 1.3, 1.4, 1.5
row=2 2.3, 2.4, 2.5
row=3 3.4, 3.5
row=4 4.5

Seems true. Can we use that value? Yes:

row=1 row.2, row.3, row.4, row.5
row=2 row.3, row.4, row.5
row=3 row.4, row.5
row=4 row.5

Is there any other bit that could be based on the row? Yes:

row=1 row.(row+1), row.3, row.4, row.5
row=2 row.(row+1), row.4, row.5
row=3 row.(row+1), row.5
row=4 row.(row+1)

What else? How many columns do we have?

row=1 cols=4 row.(row+1), row.3, row.4, row.5
row=2 cols=3 row.(row+1), row.4, row.5
row=3 cols=2 row.(row+1), row.5
row=4 cols=1 row.(row+1)

The number of columns seems to be (max_num-row) in every case and there are (max_num-1) rows in total.

A different (but not better) approach to the delimiter:

#include <iostream>

int main()
{
   const int max_num { 5 };

   for ( int row { 1 }; row < max_num; ++row )
   {
      std::cout << row << '.' << row+1;
      for ( int j { row + 2 }; j <= max_num; ++j )
      {
         std::cout << ", " << row << '.' << j;
      }
      std::cout << '\n';
   }
}

[seeplus]

#include <iostream>

int main() {
	constexpr int max_num { 5 };

	for (int i { 1 }; i < max_num; ++i)
		for (int j { i + 1 }; j <= max_num; ++j)
			std::cout << i << '.' << j << (j != max_num ? ", " : "\n");
}

1.2, 1.3, 1.4, 1.5
2.3, 2.4, 2.5
3.4, 3.5
4.5

or using std::format:

#include <iostream>
#include <iterator>
#include <format>

int main() {
	constexpr int max_num { 5 };

	for (int i { 1 }; i < max_num; ++i)
		for (int j { i + 1 }; j <= max_num; ++j)
			std::format_to(std::ostream_iterator<char>(std::cout), "{}.{}{}", i, j, j != max_num ? ", " : "\n");
}

[anup30]

if it's fixed output

#include <iostream>

int main()
{
	std::cout<<"1.2, 1.3, 1.4, 1.5\n2.3, 2.4, 2.5\n3.4, 3.5\n4.5";
}

i know it feels like troll like, but i believe it's correct solution as problem stated

[deleted account xyzzy]

@anup30, the point of the exercise was to deal with dueling for loops.