C++ program to print Floyd's triangle

Here are four different C++ programs on Floyd's triangle. First program print Floyd's triangle using for-loop, second program print Floyd's triangle using pointers, third program print Floyd's triangle using recursion and fourth program print Floyd's triangle using function.
Floyd's triangle is a right angled triangle of natural numbers. A sample Floyd's triangle with 4 rows is shown below.
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C++ program to print Floyd's triangle using for-loop

#include<iostream>
using namespace std;
int main()
{
       int row,i,j,k,s=1;
       cout<<"Enter the value ";
       cin>>row;
       for(i=0;i<row;i++)
      {
            for(k=0;k<=i;k++,s++)
                   cout<<s<<" ";
             cout<<endl;
      }
       return 0;
}

C++ program to print Floyd's triangle using pointers

#include<iostream>
#include<stdio.h>
using namespace std;
int main()
{
       int row,i,j,k=1,*p;
       p=&k;
       cout<<"Enter the value ";
       cin>>row;
       for(i=0;i<row;i++)
       {
            for(j=0;j<=i;j++)
            {
                cout<<*p<<" ";
                *p=*p+1;
            }
            cout<<endl;
       }
       return 0;
}

C++ program to print Floyd's triangle using recursion

#include<iostream>
using namespace std;
void print(int col,int s,int i)
{
    if(col>i)
        return;
    cout<<s<<" ";
    print(col+1,s+1,i);
}
void floyd(int row,int s,int i)
{
    if(row==0)
        return;
    print(0,s,i);
    cout<<endl;
    floyd(row-1,s+i+1,i+1);
}
int main()
{
       int row,i=0,s=1;
       cout<<"Enter the value ";
       cin>>row;
       floyd(row,s,i);
       return 0;
}

C++ program to print Floyd's triangle using function

#include<iostream>
using namespace std;
void floyd(int row)
{
    int i=0,j=0,s=1;
    while(i<row)
    {
        while(j<=i)
        {
            cout<<s++<<" ";
            j++;
        }
        i++,j=0;
        cout<<endl;
    }
}
int main()
{
       int row,i=0,s=1;
       cout<<"Enter the value ";
       cin>>row;
       floyd(row);
       return 0;
}