Submission #7451777

---

Source Code Expand

using System;
using System.Collections.Generic;
using System.Linq;
using static System.Console;
using System.Runtime.CompilerServices;
using static MyUtil;

class MyUtil
{
    public static void AssertEquals<T>(
				       T expected,
				       T actual,
				       [CallerLineNumber] int lno = 0
				       )
	where T : IComparable
    {
	if (expected.CompareTo(actual) != 0)
	{
	    WriteLine($"Assertion Error at line {lno}:");
	    WriteLine($"\texpected: {expected}");
	    WriteLine($"\t  actual: {actual}");
	    Environment.Exit(1);
	}
    }
}

class Program
{
    static bool isEven(int x){ return (x&1) == 0; }
    static bool isOdd(int x){ return !isEven(x); }
    
    public static void Main()
    {
	int n = int.Parse(ReadLine());
	int[] a = new int[n];
	for (int i = 0; i < n; i++)
	    a[i] = int.Parse(ReadLine());

	Array.Sort(a);
	Array.Reverse(a);
	
	int[] nP2 = new int[2];
	int[] nP1 = new int[2];
	int[] nM1 = new int[2];
	int[] nM2 = new int[2];

	// case P1 < P2 > P3 < P4 > P5
	nP2[0] = isOdd(n) ? n/2 : n/2 - 1;
	nP1[0] = isEven(n) ? 1 : 0;
	nM1[0] = isOdd(n) ? 2 : 1;
	nM2[0] = n/2 - 1;
	AssertEquals(nP2[0]+nP1[0]+nM1[0]+nM2[0], n);

    	// case P1 > P2 < P3 > P4 < P5
	nP2[1] = n/2 - 1;
	nP1[1] = isOdd(n) ? 2 : 1;
	nM1[1] = isEven(n) ? 1 : 0;
	nM2[1] = isOdd(n) ? n/2 : n/2 - 1;
	AssertEquals(nP2[1]+nP1[1]+nM1[1]+nM2[1], n);

	long[] ans = new long[2];
	for (int i = 0; i < 2; i++)
	{
	    int ct = 0;
	    for (int j = 0; j < nP2[i]; j++)
		ans[i] += 2L * a[ct++];
	    for (int j = 0; j < nP1[i]; j++)
		ans[i] += a[ct++];
	    for (int j = 0; j < nM1[i]; j++)
		ans[i] -= a[ct++];
	    for (int j = 0; j < nM2[i]; j++)
		ans[i] -= 2L * a[ct++];
	}
	WriteLine(Math.Max(ans[0], ans[1]));
    }	
}

Submission Info

Judge Result