結果

問題 No.340 雪の足跡
ユーザー eitaho
提出日時 2016-03-23 14:41:10
言語 C#(csc)
(csc 3.9.0)
結果
AC  
実行時間 936 ms / 1,000 ms
コード長 5,482 bytes
コンパイル時間 1,286 ms
コンパイル使用メモリ 112,512 KB
実行使用メモリ 81,460 KB
最終ジャッジ日時 2024-10-01 21:25:59
合計ジャッジ時間 16,842 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge1
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 * 5
other AC * 32
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 #
プレゼンテーションモードにする

using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using System.Diagnostics;
using System.Numerics;
using Enu = System.Linq.Enumerable;
class Program
{
    static readonly int INF = (int)1e9;
    static readonly string Impossible = "Odekakedekinai..";
    static readonly int[] DR = { 0, 1, 0, -1 };
    static readonly int[] DC = { 1, 0, -1, 0 };
    public void Solve()
    {
        int W = Reader.Int(), H = Reader.Int(), N = Reader.Int();
        var table = Reader.IntTable(N * 2);
        var row = Enu.Range(0, H).Select(i => new List<Position>()).ToArray();
        var col = Enu.Range(0, W).Select(i => new List<Position>()).ToArray();
        for (int ti = 1; ti < N * 2; ti += 2)
        {
            var t = table[ti];
            for (int i = 0; i + 1 < t.Length; i++)
            {
                int r = t[i] / W, c = t[i] % W;
                int nr = t[i + 1] / W, nc = t[i + 1] % W;
                if (r != nr)
                {
                    col[c].Add(new Position(Math.Min(r, nr), 1));
                    col[c].Add(new Position(Math.Max(r, nr), -1));
                }
                else
                {
                    row[r].Add(new Position(Math.Min(c, nc), 1));
                    row[r].Add(new Position(Math.Max(c, nc), -1));
                }
            }
        }
        bool[, ,] G = new bool[H, W, 4];
        for (int r = 0; r < H; r++)
        {
            int last = 0, balance = 0;
            row[r].Sort();
            foreach (var p in row[r])
            {
                if (balance > 0)
                    for (int c = last; c < p.Pos; c++)
                        G[r, c, 0] = G[r, c + 1, 2] = true;
                balance += p.Delta;
                last = p.Pos;
            }
        }
        for (int c = 0; c < W; c++)
        {
            int last = 0, balance = 0;
            col[c].Sort();
            foreach (var p in col[c])
            {
                if (balance > 0)
                    for (int r = last; r < p.Pos; r++)
                        G[r, c, 1] = G[r + 1, c, 3] = true;
                balance += p.Delta;
                last = p.Pos;
            }
        }
        int ans = BFS(G, H, W);
        Console.WriteLine(ans == INF ? Impossible : ans + "");
    }
    struct Position : IComparable<Position>
    {
        public int Pos;
        public int Delta;
        public Position(int Pos, int Delta)
        {
            this.Pos = Pos;
            this.Delta = Delta;
        }
        public int CompareTo(Position other)
        {
            return Pos - other.Pos;
        }
        public override string ToString()
        {
            return "Pos:" + Pos + " Delta:" + Delta;
        }
    }
    private int BFS(bool[, ,] G, int H, int W)
    {
        if (H == 1 && W == 1) return 0;
        var minCost = new int[H, W];
        for (int r = 0; r < H; r++)
            for (int c = 0; c < W; c++)
                minCost[r, c] = INF;
        minCost[0, 0] = 0;
        var que = new Queue<int>();
        que.Enqueue(0); que.Enqueue(0);
        while (que.Count > 0)
        {
            int r = que.Dequeue(), c = que.Dequeue();
            for (int d = 0; d < DR.Length; d++)
                if (G[r, c, d])
                {
                    int nr = r + DR[d], nc = c + DC[d];
                    int nextCost = minCost[r, c] + 1;
                    if (nextCost < minCost[nr, nc])
                    {
                        if (nr == H - 1 && nc == W - 1) return nextCost;
                        minCost[nr, nc] = nextCost;
                        que.Enqueue(nr); que.Enqueue(nc);
                    }
                }
        }
        return INF;
    }
}
class Entry { static void Main() { new Program().Solve(); } }
class Reader
{
    private static TextReader reader = Console.In;
    private static readonly char[] separator = { ' ' };
    private static readonly StringSplitOptions op = StringSplitOptions.RemoveEmptyEntries;
    private static string[] A = new string[0];
    private static int i;
    private static void Init() { A = new string[0]; }
    public static void Set(TextReader r) { reader = r; Init(); }
    public static void Set(string file) { reader = new StreamReader(file); Init(); }
    public static bool HasNext() { return CheckNext(); }
    public static string String() { return Next(); }
    public static int Int() { return int.Parse(Next()); }
    public static long Long() { return long.Parse(Next()); }
    public static double Double() { return double.Parse(Next()); }
    public static int[] IntLine() { return Array.ConvertAll(Split(Line()), int.Parse); }
    public static int[] IntArray(int N) { return Enu.Range(0, N).Select(i => Int()).ToArray(); }
    public static int[][] IntTable(int H) { return Enu.Range(0, H).Select(i => IntLine()).ToArray(); }
    public static string[] StringArray(int N) { return Enu.Range(0, N).Select(i => Next()).ToArray(); }
    public static string Line() { return reader.ReadLine().Trim(); }
    private static string[] Split(string s) { return s.Split(separator, op); }
    private static string Next() { CheckNext(); return A[i++]; }
    private static bool CheckNext()
    {
        if (i < A.Length) return true;
        string line = reader.ReadLine();
        if (line == null) return false;
        if (line == "") return CheckNext();
        A = Split(line);
        i = 0;
        return true;
    }
}
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