Problem: 2062C - Cirno and Operations
Language: java

Solution 1 (runtime: 327 ms):
import java.util.Arrays;
import java.util.Scanner;
import java.util.stream.IntStream;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);

    int t = sc.nextInt();
    for (int tc = 0; tc < t; ++tc) {
      int n = sc.nextInt();
      int[] a = new int[n];
      for (int i = 0; i < a.length; ++i) {
        a[i] = sc.nextInt();
      }

      System.out.println(solve(a));
    }

    sc.close();
  }

  static long solve(int[] a) {
    long[] values = Arrays.stream(a).asLongStream().toArray();

    long result = Arrays.stream(values).sum();
    while (values.length != 1) {
      long[] values_ = values;
      values =
          IntStream.range(0, values.length - 1)
              .mapToLong(i -> values_[i + 1] - values_[i])
              .toArray();

      result = Math.max(result, Math.abs(Arrays.stream(values).sum()));
    }

    return result;
  }
}


Solution 2 (runtime: 140 ms):
import java.io.*;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.stream.Collectors;



public class Main {
    static int MOD = (int) (1e9+7);
    static InputReader in = new InputReader(System.in);
    static PrintWriter out = new PrintWriter(System.out, false);
    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;
        public int nextInt() {
            return Integer.parseInt(next());
        }
        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }
        public long nextLong() {
            return Long.parseLong(next());
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }
    }
    static List<Long> list = new ArrayList<>();
    public static void main(String[] args) throws Exception {

        Main main = new Main();
        int T = in.nextInt();
        while (T-- > 0){
            main.solve();
        }
        out.flush();
    }

    void solve() {
        int n = in.nextInt();
        List<Long> list = new ArrayList<>();
        long sum = 0;
        for (int i = 0; i < n; i++) {
            long t = in.nextInt();
            list.add(t);
            sum += t;
        }
        long max = sum;
        while (list.size() > 1){
            List<Long> list0 = new ArrayList<>();
            sum = 0;
            for (int i = 1; i < list.size(); i++) {
                long t = list.get(i) - list.get(i - 1);
                list0.add(t);
                sum += t;
            }
            if(sum < 0) sum *= -1;
            max = Math.max(max, sum);
            list = list0;

        }
        out.println(max);
    }





}