butterflypattern.java

import java.util.Scanner;

public class butterflypattern {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n= sc.nextInt();
        for (int i = 1;i<=n;i++){
            for (int j=1;j<=i;j++){
                System.out.print("*"+" ");
            }
            int s = 2*(n-i);
            for (int j =1;j<=s;j++){
                System.out.print("  ");
            }
            for (int j = 1; j<=i;j++){
                System.out.print("*"+" ");
            }
            System.out.println();
        }
        for (int i = n;i>=1;i--) {
            for (int j = 1; j <= i; j++) {
                System.out.print("*" + " ");
            }
            int s = 2*(n-i);
            for (int j = 1; j <= s; j++) {
                System.out.print("  ");
            }
            for (int j = 1; j <= i; j++) {
                System.out.print("*" + " ");
            }
            System.out.println();
        }
    }
}