Problem: 2062C - Cirno and Operations
Language: java

Solution 1 (runtime: 171 ms):
import java.math.BigInteger;
import java.util.*;

public class Cirno {
    static Scanner sc = new Scanner(System.in);

    static BigInteger bsum = BigInteger.valueOf(Integer.MIN_VALUE);
    static boolean c = true;

    static void diffFinder(BigInteger arr[]) {
        BigInteger sum = BigInteger.ZERO;

        for (int i = 0; i < arr.length; i++) {
            sum = sum.add(arr[i]);
        }
        if (c)
            c = false;
        else
            sum = sum.abs();
        if (sum.compareTo(bsum) > 0) {
            bsum = sum;
        }

        if (arr.length <= 1)
            return;
        else {
            BigInteger sys[] = new BigInteger[arr.length - 1];

            for (int i = 0; i < arr.length - 1; i++) {
                sys[i] = arr[i + 1].subtract(arr[i]);
            }

            diffFinder(sys);
        }
    }

    public static void main(String[] args) {
        int t = sc.nextInt();
        while (t-- > 0) {
            int n = sc.nextInt();
            BigInteger arr[] = new BigInteger[n];
            for (int i = 0; i < n; i++) {
                arr[i] = BigInteger.valueOf(sc.nextInt());
            }
            if (n == 1) {
                System.out.println(arr[0]);
            } else {
                diffFinder(arr);
                System.out.println(bsum);
                c = true;
                bsum = BigInteger.valueOf(Integer.MIN_VALUE);
            }
        }
    }
}


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);
    }





}