結果

問題 No.121 傾向と対策：門松列（その２）
ユーザー 紙ぺーぱー紙ぺーぱー
提出日時 2015-06-25 18:02:01
言語 C#(csc)
(csc 3.9.0)
結果
AC  
実行時間 2,061 ms / 5,000 ms
コード長 6,604 bytes
コンパイル時間 1,168 ms
コンパイル使用メモリ 112,000 KB
実行使用メモリ 61,208 KB
最終ジャッジ日時 2024-06-28 18:36:07
合計ジャッジ時間 7,376 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge5
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 72 ms
21,248 KB
testcase_01 AC 97 ms
21,888 KB
testcase_02 AC 31 ms
18,768 KB
testcase_03 AC 752 ms
23,424 KB
testcase_04 AC 2,061 ms
61,208 KB
testcase_05 AC 783 ms
23,552 KB
testcase_06 AC 293 ms
21,760 KB
testcase_07 AC 461 ms
21,760 KB
testcase_08 AC 870 ms
23,552 KB
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コンパイルメッセージ
Microsoft (R) Visual C# Compiler version 3.9.0-6.21124.20 (db94f4cc)
Copyright (C) Microsoft Corporation. All rights reserved.

ソースコード

diff # 

using System;
using System.Linq;
using System.Diagnostics;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;

namespace Program
{

    public class Solver
    {
        public void Solve()
        {
            var n = sc.Integer();
            var a = sc.Integer(n);
            var Xs = a.Distinct().ToList();
            Xs.Add(-1);
            Xs.Sort();
            long sum = 0;
            var size = Xs.Count;
            long intersect = 0;
            var left = new FenwickTree(size);
            var right = new FenwickTree(size);
            for (int i = 0; i < n; i++)
            {
                var p = Xs.BinarySearch(a[i]);
                right.Add(p, 1);
            }
            for (int i = 0; i < n; i++)
            {
                var p = Xs.BinarySearch(a[i]);
                intersect -= left[p, p] * right[p, p];
                right.Add(p, -1);
                {
                    var l = left[p - 1];
                    var r = right[p - 1];
                    sum += l * r;
                }
                {
                    var l = left[p + 1, size];
                    var r = right[p + 1, size];
                    sum += l * r;

                }
                sum -= intersect;
                left.Add(p, 1);
                intersect += left[p, p] * right[p, p];
                Debug.WriteLine(sum);
            }
            IO.Printer.Out.WriteLine(sum);
        }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}

#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer : StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != '-' && (b < '0' || '9' < b));
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { return double.Parse(Scan(), CultureInfo.InvariantCulture); }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion
#region FenwickTree
[System.Diagnostics.DebuggerDisplay("Data={ToString()}")]
public class FenwickTree
{
    int n;
    long[] bit;
    int max = 1;
    public FenwickTree(int size)
    {
        n = size; bit = new long[n + 1];
        while ((max << 1) <= n) max <<= 1;
    }
    /// <summary>sum[a,b]</summary>
    public long this[int i, int j] { get { return this[j] - this[i - 1]; } }
    /// <summary>sum[0,i]</summary>
    public long this[int i] { get { long s = 0; for (; i > 0; i -= i & -i) s += bit[i]; return s; } }
    public int LowerBound(long w)
    {
        if (w <= 0) return 0;
        int x = 0;
        for (int k = max; k > 0; k >>= 1)
            if (x + k <= n && bit[x + k] < w)
            {
                w -= bit[x + k];
                x += k;
            }
        return x + 1;
    }
    /// <summary>add v to bit[i]</summary>
    public void Add(int i, long v)
    {
        if (i == 0) System.Diagnostics.Debug.Fail("BIT is 1 indexed");
        for (; i <= n; i += i & -i) bit[i] += v;
    }
    public override string ToString() { return string.Join(",", Enumerable.Range(0, n + 1).Select(i => this[i, i])); }
}
#endregion
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