蓝桥杯2019年第十届真题-灵能传输-题解（Java代码）

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
//import java.util.Scanner;
public class Main {
    private static long[] a;
    private static long[] s;
    private static boolean[] st;
    private static int n;
    public static void main(String[] args) throws NumberFormatException, IOException {
        int T;
        //Scanner sc = new Scanner(System.in);
        BufferedReader sc = new BufferedReader(new InputStreamReader(System.in));
        //T = sc.nextInt();
        T = Integer.parseInt(sc.readLine().trim());
        while(T-- > 0) {
            //n = sc.nextInt();
            n = Integer.parseInt(sc.readLine().trim());
            String[] arr = sc.readLine().trim().split(" ");
            a = new long[n + 1];
            s = new long[n + 1];
            st = new boolean[n + 1];
            s[0] = 0;
            for(int i = 1; i <= n; i++) {
                //s[i] = sc.nextLong();
                s[i] = Integer.parseInt(arr[i - 1]);
                s[i] += s[i - 1];
            }
            long s0 = s[0], sn = s[n];
            if(s0 > sn) {
                long temp = s0;
                s0 = sn;
                sn = temp;
            }
            Arrays.sort(s);
            for(int i = 0; i <= n; i++) {
                if(s[i] == s0) {
                    s0 = i;
                    break;
                }
            }
            for (int i = n; i >= 0; i--) {
                if(s[i] == sn) {
                    sn = i;
                    break;
                }
            }
            int l = 0, r = n;
            for(int i = (int)s0; i >= 0; i -= 2) {
                a[l++] = s[i];
                st[i] = true;
            }
            for(int i = (int)sn; i <= n; i += 2) {
                a[r--] = s[i];
                st[i] = true;
            }
            for(int i = 0; i <= n; i++) {
                if(!st[i]) {
                    a[l++] = s[i];
                }
            }
            long res = 0;
            for(int i = 1; i <= n; i++) {
                if(Math.abs(a[i] - a[i - 1]) > res) {
                    res = Math.abs(a[i] - a[i - 1]);
                }
            }
            System.out.println(res);
        }
    }
}