結果

問題 No.196 典型DP (1)
ユーザー eitahoeitaho
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
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 3
other AC * 41
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 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;
}
}
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