/* * @ Javier Felipe Toribio 2018 * * challenge: * * Print the pattern 2 * */ import java.util.*; import java.util.function.*; import java.util.stream.*; public class Program { public static void showPattern (int max, Function,String> op, boolean reverse) { List arr = new ArrayList<>(); List intList = IntStream.rangeClosed(1,max*(max+1)/2). boxed(). collect(Collectors.toList()); for(int i=1;i<=max;i++) { List lst = intList.subList (((i-1)*i/2),(i*(i+1)/2)); arr.add(op.apply(lst)); } if(reverse) { Collections.reverse(arr); } arr.stream().forEachOrdered (System.out::println); } public static void main(String[] args) { // Number of rows int max = (new Scanner(System.in)).nextInt(); // Patterns and their reverses List,String>> ops = List.of (arr -> String. join(" ", arr.stream(). map(i -> (i*i)+""). collect(Collectors.toList())), arr -> { List a = new ArrayList<>(arr); Collections.reverse(a); return String. join(" ", a.stream(). map(i -> i+""). collect(Collectors.toList())); }, arr -> String.join(" ", arr.stream(). map(i -> Character.toString ((char)((2*i-2)%26+65)) + " " + Character.toString ((char)((2*i-1)%26+65))). collect(Collectors.toList()))); for(boolean rev : List.of(false,true)){ for(Function, String> op : ops) { showPattern(max,op,rev); System.out.println(); } } // Last patterns for(Integer i : List.of(3,4,5,6,5,4,3)) System.out.println(String.join("", Collections.nCopies(i,"#"))); System.out.println(); for(Integer i : List.of(6,5,4,3,4,5,6)) System.out.println(String.join("", Collections.nCopies(i,"#"))); } }

[challenge] print the pattern 2