結果

問題 No.956 Number of Unbalanced
コンテスト
ユーザー りあん
提出日時 2019-12-19 01:52:36
言語 C#(csc)
(csc 3.9.0)
結果
AC  
実行時間 141 ms / 2,000 ms
コード長 8,897 bytes
コンパイル時間 1,249 ms
コンパイル使用メモリ 124,176 KB
実行使用メモリ 51,568 KB
最終ジャッジ日時 2024-07-06 23:17:08
合計ジャッジ時間 5,070 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge3
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 6
other AC * 24
権限があれば一括ダウンロードができます
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.Collections.Generic;
using System.Linq;
using System.IO;
using System.Threading;
using System.Text;
using System.Diagnostics;
using static util;
using P = pair<int, int>;

class Program {
    static void Main(string[] args) {
        var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
        var solver = new Solver(sw);
        // var t = new Thread(solver.solve, 1 << 26); // 64 MB
        // t.Start();
        // t.Join();
        solver.solve();
        sw.Flush();
    }
}

class Solver {
    StreamWriter sw;
    Scan sc;
    void Prt(string a) => sw.WriteLine(a);
    void Prt<T>(IEnumerable<T> a) => Prt(string.Join(" ", a));
    void Prt(params object[] a) => Prt(string.Join(" ", a));
    public Solver(StreamWriter sw) {
        this.sw = sw;
        this.sc = new Scan();
    }

    long solve(int[] a) {
        int n = a.Length;
        var lis = new List<int>[100010];
        for (int i = 0; i < 100010; i++)
        {
            lis[i] = new List<int>();
        }
        for (int i = 0; i < n; i++)
        {
            lis[a[i]].Add(i + 1);
        }
        long ans = 0;
        for (int i = 0; i < 100010; i++)
        {
            if (lis[i].Count == 0) continue;
            var st = new Stack<P>();
            var st2 = new Stack<P>();
            st.Push(new P(0, 0));
            st2.Push(new P(0, 0));
            var dic = new Dictionary<int, long>();
            dic.Add(0, 0);
            int pd = 0, pj = 0;
            foreach (var j in lis[i])
            {
                int d = pd - (j - pj - 1) + 1;
                if (pj != j - 1 && dic.ContainsKey(d - 1)) {
                    ans += dic[d - 1];
                }

                while (st.Count > 0 && st.Peek().v1 < d) {
                    st.Pop();
                }
                bool fir = true;
                while (st2.Count > 0 && st2.Peek().v1 >= d) {
                    if (!fir)
                        ans += dic[st2.Peek().v1];
                    fir = false;
                    st2.Pop();
                }
                if (st.Count > 0) {
                    int k = st.Peek().v2 + st.Peek().v1 - d;
                    if (!dic.ContainsKey(d)) {
                        dic.Add(d, 0);
                    }
                    dic[d] += j - k - 1;
                    ans += dic[d];
                }
                else {
                    Assert(!dic.ContainsKey(d));
                    dic.Add(d, j);
                    ans += j;
                }
                st.Push(new P(d, j));
                st2.Push(new P(d, j));
                pd = d;
                pj = j;
            }
            {
                bool fir = true;
                while (st2.Count > 0 && st2.Peek().v1 >= pd - n + pj) {
                    if (!fir)
                        ans += dic[st2.Peek().v1];
                    fir = false;
                    st2.Pop();
                }
            }
        }
        return ans;
    }

    public void solve() {
        int n = sc.Int;
        var a = sc.IntArr;
        Prt(solve(a));
        // Prt(naive(a));
        // for (int i = 0; i < (1 << n); i++)
        // {
        //     var a = new int[n];
        //     for (int j = 0; j < n; j++)
        //     {
        //         a[j] = ((i >> j) & 1) + 1;
        //     }
        //     if (solve(a) != naive(a)) {
        //         DBG(a);
        //         DBG(solve(a));
        //         DBG(naive(a));
        //     }
        // }
    }
    int naive(int[] a) {
        int n = a.Length;
        int m = a.Max() + 9;
        int ans = 0;
        int c1 = 0, c2 = 0;
        for (int i = 0; i < n; i++)
        {
            var cnt = new int[m];
            for (int j = i; j < n; j++)
            {
                ++cnt[a[j]];
                if (cnt.Max() * 2 > j - i + 1) ++ans;
                if (cnt[1] * 2 > j - i + 1) ++c1;
                if (cnt[2] * 2 > j - i + 1) ++c2;
            }
        }
        // DBG(c1, c2);
        return ans;
    }
}

class pair<T, U> : IComparable<pair<T, U>> {
    public T v1;
    public U v2;
    public pair() : this(default(T), default(U)) {}
    public pair(T v1, U v2) { this.v1 = v1; this.v2 = v2; }
    public int CompareTo(pair<T, U> a) {
        int c = Comparer<T>.Default.Compare(v1, a.v1);
        return c != 0 ? c : Comparer<U>.Default.Compare(v2, a.v2);
    }
    public override string ToString() => v1 + " " + v2;
    public void Deconstruct(out T a, out U b) { a = v1; b = v2; }
}
static class util {
    public static readonly int M = 1000000007;
    // public static readonly int M = 998244353;
    public static readonly long LM = 1L << 60;
    public static readonly double eps = 1e-11;
    public static void DBG(string a) => Console.Error.WriteLine(a);
    public static void DBG<T>(IEnumerable<T> a) => DBG(string.Join(" ", a));
    public static void DBG(params object[] a) => DBG(string.Join(" ", a));
    public static void Assert(bool cond) { if (!cond) throw new Exception(); }
    public static pair<T, U> make_pair<T, U>(T v1, U v2) => new pair<T, U>(v1, v2);
    public static int CompareList<T>(IList<T> a, IList<T> b) where T : IComparable<T> {
        for (int i = 0; i < a.Count && i < b.Count; i++)
            if (a[i].CompareTo(b[i]) != 0) return a[i].CompareTo(b[i]);
        return a.Count.CompareTo(b.Count);
    }
    public static bool inside(int i, int j, int h, int w) => i >= 0 && i < h && j >= 0 && j < w;
    static readonly int[] dd = { 0, 1, 0, -1 };
    // static readonly string dstring = "RDLU";
    public static P[] adjacents(int i, int j)
        => Enumerable.Range(0, dd.Length).Select(k => new P(i + dd[k], j + dd[k ^ 1])).ToArray();
    public static P[] adjacents(int i, int j, int h, int w)
        => Enumerable.Range(0, dd.Length).Select(k => new P(i + dd[k], j + dd[k ^ 1]))
                                         .Where(p => inside(p.v1, p.v2, h, w)).ToArray();
    public static P[] adjacents(this P p) => adjacents(p.v1, p.v2);
    public static P[] adjacents(this P p, int h, int w) => adjacents(p.v1, p.v2, h, w);
    public static Dictionary<T, int> compress<T>(this IEnumerable<T> a)
        => a.Distinct().OrderBy(v => v).Select((v, i) => new { v, i }).ToDictionary(p => p.v, p => p.i);
    public static Dictionary<T, int> compress<T>(params IEnumerable<T>[] a) => compress(a.Aggregate(Enumerable.Union));
    public static T[] inv<T>(this Dictionary<T, int> dic) {
        var res = new T[dic.Count];
        foreach (var item in dic) res[item.Value] = item.Key;
        return res;
    }
    public static void swap<T>(ref T a, ref T b) where T : struct { var t = a; a = b; b = t; }
    public static void swap<T>(this IList<T> a, int i, int j) where T : struct { var t = a[i]; a[i] = a[j]; a[j] = t; }
    public static T[] copy<T>(this IList<T> a) {
        var ret = new T[a.Count];
        for (int i = 0; i < a.Count; i++) ret[i] = a[i];
        return ret;
    }
}

class Scan {
    StreamReader sr;
    public Scan() { sr = new StreamReader(Console.OpenStandardInput()); }
    public Scan(string path) { sr = new StreamReader(path); }
    public int Int => int.Parse(Str);
    public long Long => long.Parse(Str);
    public double Double => double.Parse(Str);
    public string Str => sr.ReadLine().Trim();
    public pair<T, U> Pair<T, U>() {
        T a; U b;
        Multi(out a, out b);
        return new pair<T, U>(a, b);
    }
    public P P => Pair<int, int>();
    public int[] IntArr => StrArr.Select(int.Parse).ToArray();
    public long[] LongArr => StrArr.Select(long.Parse).ToArray();
    public double[] DoubleArr => StrArr.Select(double.Parse).ToArray();
    public string[] StrArr => Str.Split(new[]{' '}, StringSplitOptions.RemoveEmptyEntries);
    bool eq<T, U>() => typeof(T).Equals(typeof(U));
    T ct<T, U>(U a) => (T)Convert.ChangeType(a, typeof(T));
    T cv<T>(string s) => eq<T, int>()    ? ct<T, int>(int.Parse(s))
                       : eq<T, long>()   ? ct<T, long>(long.Parse(s))
                       : eq<T, double>() ? ct<T, double>(double.Parse(s))
                       : eq<T, char>()   ? ct<T, char>(s[0])
                                         : ct<T, string>(s);
    public void Multi<T>(out T a) => a = cv<T>(Str);
    public void Multi<T, U>(out T a, out U b)
    { var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]); }
    public void Multi<T, U, V>(out T a, out U b, out V c)
    { var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); }
    public void Multi<T, U, V, W>(out T a, out U b, out V c, out W d)
    { var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); d = cv<W>(ar[3]); }
    public void Multi<T, U, V, W, X>(out T a, out U b, out V c, out W d, out X e)
    { var ar = StrArr; a = cv<T>(ar[0]); b = cv<U>(ar[1]); c = cv<V>(ar[2]); d = cv<W>(ar[3]); e = cv<X>(ar[4]); }
}
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