結果
問題 | No.196 典型DP (1) |
ユーザー | eitaho |
提出日時 | 2015-06-12 18:02:21 |
言語 | C#(csc) (csc 3.9.0) |
結果 |
AC
|
実行時間 | 137 ms / 2,000 ms |
コード長 | 3,109 bytes |
コンパイル時間 | 1,005 ms |
コンパイル使用メモリ | 116,864 KB |
実行使用メモリ | 63,208 KB |
最終ジャッジ日時 | 2024-07-06 15:52:10 |
合計ジャッジ時間 | 5,856 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 41 |
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
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 Mod = (int)1e9 + 7;int N, K;List<int>[] G;int[][] Count;int[] Size;public void Solve(){N = Reader.Int();K = Reader.Int();G = Enu.Range(0, N).Select(i => new List<int>()).ToArray();foreach (var e in Reader.IntTable(N - 1)){G[e[0]].Add(e[1]);G[e[1]].Add(e[0]);}Count = new int[N][];Size = new int[N];Rec(0, -1);Console.WriteLine(Count[0][K]);}void Rec(int v, int prev){if (Count[v] != null) return;Count[v] = new int[N + 1];Count[v][0] = 1;Size[v] = 1;foreach (int child in G[v])if (child != prev){Rec(child, v);int[] next = new int[N + 1];for (int a = 0; a <= Size[v]; a++)for (int b = 0; b <= Size[child]; b++)next[a + b] = (int)((next[a + b] + (long)Count[v][a] * Count[child][b]) % Mod);Count[v] = next;Size[v] += Size[child];}Count[v][Size[v]] = 1;}}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 => Line()).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;}}