Submission #48803672

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Source Code Expand

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;

namespace Tasks;

public class C
{
    public static void Main()
    {
        using var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true };
        Console.SetOut(sw);
        Solve();
        Console.Out.Flush();
    }

    public static void Solve()
    {
        var (N, K) = Scanner.Scan<int, int>();
        var A = Scanner.ScanEnumerable<int>().ToArray();
        var cumL = new long[K + 1];
        var cumR = new long[K + 1];
        for (var i = 0; i < K; i++)
        {
            cumL[i + 1] += cumL[i];
            if (i % 2 == 1) cumL[i + 1] += A[i] - A[i - 1];
        }

        Array.Reverse(A);
        for (var i = 0; i < K; i++)
        {
            cumR[i + 1] += cumR[i];
            if (i % 2 == 1) cumR[i + 1] += A[i - 1] - A[i];
        }

        Array.Reverse(cumR);

        const long Inf = 1L << 60;
        var answer = Inf;
        for (var i = 0; i < K; i += 2)
        {
            answer = Math.Min(answer, cumL[i] + cumR[i]);
        }

        Console.WriteLine(answer);
    }

    public static class Scanner
    {
        public static T Scan<T>() where T : IConvertible => Convert<T>(ScanStringArray()[0]);
        public static (T1, T2) Scan<T1, T2>() where T1 : IConvertible where T2 : IConvertible
        {
            var input = ScanStringArray();
            return (Convert<T1>(input[0]), Convert<T2>(input[1]));
        }
        public static (T1, T2, T3) Scan<T1, T2, T3>() where T1 : IConvertible where T2 : IConvertible where T3 : IConvertible
        {
            var input = ScanStringArray();
            return (Convert<T1>(input[0]), Convert<T2>(input[1]), Convert<T3>(input[2]));
        }
        public static (T1, T2, T3, T4) Scan<T1, T2, T3, T4>() where T1 : IConvertible where T2 : IConvertible where T3 : IConvertible where T4 : IConvertible
        {
            var input = ScanStringArray();
            return (Convert<T1>(input[0]), Convert<T2>(input[1]), Convert<T3>(input[2]), Convert<T4>(input[3]));
        }
        public static (T1, T2, T3, T4, T5) Scan<T1, T2, T3, T4, T5>() where T1 : IConvertible where T2 : IConvertible where T3 : IConvertible where T4 : IConvertible where T5 : IConvertible
        {
            var input = ScanStringArray();
            return (Convert<T1>(input[0]), Convert<T2>(input[1]), Convert<T3>(input[2]), Convert<T4>(input[3]), Convert<T5>(input[4]));
        }
        public static (T1, T2, T3, T4, T5, T6) Scan<T1, T2, T3, T4, T5, T6>() where T1 : IConvertible where T2 : IConvertible where T3 : IConvertible where T4 : IConvertible where T5 : IConvertible where T6 : IConvertible
        {
            var input = ScanStringArray();
            return (Convert<T1>(input[0]), Convert<T2>(input[1]), Convert<T3>(input[2]), Convert<T4>(input[3]), Convert<T5>(input[4]), Convert<T6>(input[5]));
        }
        public static IEnumerable<T> ScanEnumerable<T>() where T : IConvertible => ScanStringArray().Select(Convert<T>);
        private static string[] ScanStringArray()
        {
            var line = Console.ReadLine()?.Trim() ?? string.Empty;
            return string.IsNullOrEmpty(line) ? Array.Empty<string>() : line.Split(' ');
        }
        private static T Convert<T>(string value) where T : IConvertible => (T)System.Convert.ChangeType(value, typeof(T));
    }
}

Submission Info

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