butterflypattern.cpp

#include <iostream>

using namespace std;

int main()
{
    int n;
    cout<<"Enter no of rows - ";
    cin>>n;
    int i,j;
    for(i=1;i<=n;i++)
    {
	    for(j=1;j<=i;j++)
	        cout<<"*";
	    for(j=1;j<=((n*2)-(2*i));j++)
	        cout<<" ";
	   for(j=1;j<=i;j++)
	        cout<<"*";
	    cout<<endl;
	}
	for(i=n;i>=1;i--)
    {
	    for(j=1;j<=i;j++)
	        cout<<"*";
	    for(j=1;j<=((n*2)-(2*i));j++)
	        cout<<" ";
	   for(j=1;j<=i;j++)
	        cout<<"*";
	    cout<<endl;
	}
}