C++ Program To Print Butterfly Pattern

 

Program:

#include <iostream>
using namespace std;

int main()
{
    int n;
    cout<<"Enter number of rows: ";
    cin>>n;
    
    //loop for printing upper half
    for(int i=1;i<=n;i++)   //loop to terminate line
    {
        for(int j=1;j<=i;j++)   //loop to print *
        cout<<"* ";
        
        for(int j=1;j<=2*n-2*i;j++) //loop to print spaces
        cout<<"  ";
        
        for(int j=1;j<=i;j++)   //loop to print *
        cout<<"* ";
        
        cout<<endl;
    }

    //loop for printing lower half
    for(int i=n;i>=1;i--)
    {
        for(int j=1;j<=i;j++)
        cout<<"* ";
        
        for(int j=1;j<=2*n-2*i;j++)
        cout<<"  ";
        
        for(int j=1;j<=i;j++)
        cout<<"* ";
        
        cout<<endl;
    }
    return 0;
}

Output:

*        *

**      **

***    ***

****  ****

**********

**********

****  ****

***    ***

**      **

*        *