10038 - Jolly Jumpers

JollyJumper.java

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.StringTokenizer;
 
public class JollyJumper {
 public static String JOLLY = "Jolly";
 public static String NOT_JOLLY = "Not jolly";
 
 public static void main(String[] args) {
  Scanner scanner = new Scanner(System.in);
  StringTokenizer tokenizer;
  int numberOfItems;
  while (scanner.hasNext()) {
   tokenizer = new StringTokenizer(scanner.nextLine());
   numberOfItems = Integer.parseInt(tokenizer.nextToken());
   int[] numbers = new int[numberOfItems];
   for (int i = 0; i < numberOfItems; i++) {
    numbers[i] = Integer.parseInt(tokenizer.nextToken());
   }
   System.out.println(isJolly(numbers));
  }
  System.exit(0);
 }
 
 private static String isJolly(int[] numbers) {
  List results = new ArrayList();
  for (int i = 0; i < numbers.length - 1; i++) {
   int result = Math.abs(numbers[i] - numbers[i + 1]);
   if (result == 0) {
    return NOT_JOLLY;
   }
   if (result >= numbers.length) {
    return NOT_JOLLY;
   }
   if (results.contains(result)) {
    return NOT_JOLLY;
   }
   results.add(result);
  }
  return JOLLY;
 }
}