結果

問題 No.1227 I hate ThREE
ユーザー uwiuwi
提出日時 2020-09-12 02:17:57
言語 Java21
(openjdk 21)
結果
AC  
実行時間 317 ms / 2,000 ms
コード長 6,062 bytes
コンパイル時間 5,319 ms
コンパイル使用メモリ 81,560 KB
実行使用メモリ 65,828 KB
最終ジャッジ日時 2023-08-30 14:55:31
合計ジャッジ時間 12,195 ms
ジャッジサーバーID
（参考情報） 		judge14 / judge12
このコードへのチャレンジ
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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 42 ms
49,388 KB
testcase_01 AC 42 ms
49,236 KB
testcase_02 AC 42 ms
49,284 KB
testcase_03 AC 65 ms
51,668 KB
testcase_04 AC 72 ms
51,656 KB
testcase_05 AC 83 ms
52,332 KB
testcase_06 AC 44 ms
49,348 KB
testcase_07 AC 43 ms
49,452 KB
testcase_08 AC 122 ms
54,940 KB
testcase_09 AC 92 ms
52,092 KB
testcase_10 AC 80 ms
52,520 KB
testcase_11 AC 302 ms
63,756 KB
testcase_12 AC 317 ms
65,212 KB
testcase_13 AC 53 ms
50,360 KB
testcase_14 AC 105 ms
54,572 KB
testcase_15 AC 124 ms
54,936 KB
testcase_16 AC 152 ms
55,512 KB
testcase_17 AC 128 ms
55,164 KB
testcase_18 AC 163 ms
61,688 KB
testcase_19 AC 145 ms
55,348 KB
testcase_20 AC 185 ms
61,716 KB
testcase_21 AC 47 ms
49,628 KB
testcase_22 AC 140 ms
55,032 KB
testcase_23 AC 215 ms
63,260 KB
testcase_24 AC 224 ms
64,812 KB
testcase_25 AC 226 ms
65,168 KB
testcase_26 AC 209 ms
63,688 KB
testcase_27 AC 225 ms
65,272 KB
testcase_28 AC 232 ms
65,120 KB
testcase_29 AC 233 ms
65,332 KB
testcase_30 AC 219 ms
65,512 KB
testcase_31 AC 230 ms
65,608 KB
testcase_32 AC 232 ms
65,200 KB
testcase_33 AC 211 ms
63,496 KB
testcase_34 AC 223 ms
65,828 KB
testcase_35 AC 210 ms
63,872 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

package contest200911;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class E2 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";

	void solve() {
//		BarrettInt bi = new BarrettInt(1000000007);
		int n = ni(), C = ni();
		int[] from = new int[n - 1];
		int[] to = new int[n - 1];
		for (int i = 0; i < n - 1; i++) {
			from[i] = ni() - 1;
			to[i] = ni() - 1;
		}
		int[][] g = packU(n, from, to);

		int mod = 1000000007;
		int[][] pars = parents(g, 0);
		int[] par = pars[0], ord = pars[1];

		long ans = 0;
		for (int j = 1; j <= 3; j++) {
			ans += solve((C - j) / 3 + 1, n, par, ord, mod, g);
		}
		out.println(ans%mod);
	}

	long solve(int C, int n, int[] par, int[] ord, int mod, int[][] g)
	{
		int T = Math.min(2*n+5, C);
		int[][] dp = new int[n][T];
		for (int i = n - 1; i >= 0; i--) {
			int cur = ord[i];
			for (int j = 0; j < T; j++) {
				long t = 1;
				for (int e : g[cur]) {
					if (par[cur] == e) continue;
					t = t * ((j - 1 >= 0 ? dp[e][j - 1] : 0) + (j + 1 < T ? dp[e][j+1] : 0)) % mod;
				}
				dp[cur][j] = (int)t;
			}
		}
		long ans = 0;
		for(int i = 0;i < T;i++){
			ans += dp[0][i];
		}
		if(T < C)ans += (long)dp[0][n+1] * (C-T);
		ans %= mod;
		return ans;
	}

	public static class BarrettInt {
		public int mod;
		public long M;
		public int h;

		public BarrettInt(int mod)
		{
			this.mod = mod;
			long K = Integer.highestOneBit(mod)<<1;
			h = Long.numberOfTrailingZeros(K)*2;
			M = K*K/mod;
		}

		public long mod(long a)
		{
			long v = M*(a&mask);
			long bl = v&mask;
			v = (v>>>31) + M*(a>>>31);
			bl |= (v&mask)<<31;

			long q = bl>>>h|v>>>31<<62-h;
			long r = a-q*mod;
			return r < mod ? r : r-mod;
		}

		public long modh(long a)
		{
			long r = a-((M*(a&mask)>>>31)+M*(a>>>31)>>>h-31)*mod;
			return r < mod ? r : r-mod;
		}

		public long modl(long a)
		{
			long r = a-(M*a>>>h)*mod;
			return r < mod ? r : r-mod;
		}

		private static final long mask = (1L<<31)-1;
	}


	public static int[][] parents(int[][] g, int root) {
		int n = g.length;
		int[] par = new int[n];
		Arrays.fill(par, -1);

		int[] depth = new int[n];
		depth[0] = 0;

		int[] q = new int[n];
		q[0] = root;
		for (int p = 0, r = 1; p < r; p++) {
			int cur = q[p];
			for (int nex : g[cur]) {
				if (par[cur] != nex) {
					q[r++] = nex;
					par[nex] = cur;
					depth[nex] = depth[cur] + 1;
				}
			}
		}
		return new int[][]{par, q, depth};
	}


	public static int[][] packU(int n, int[] from, int[] to) {
		return packU(n, from, to, from.length);
	}

	public static int[][] packU(int n, int[] from, int[] to, int sup) {
		int[][] g = new int[n][];
		int[] p = new int[n];
		for (int i = 0; i < sup; i++) p[from[i]]++;
		for (int i = 0; i < sup; i++) p[to[i]]++;
		for (int i = 0; i < n; i++) g[i] = new int[p[i]];
		for (int i = 0; i < sup; i++) {
			g[from[i]][--p[from[i]]] = to[i];
			g[to[i]][--p[to[i]]] = from[i];
		}
		return g;
	}


	void run() throws Exception
	{
//		int n = 1000, m = 99999;
//		Random gen = new Random(1);
//		StringBuilder sb = new StringBuilder();
//		sb.append(n + " ");
//		sb.append(1000000000 + " ");
//		for (int i = 0; i < n-1; i++) {
//			sb.append(i+2 + " ");
//			sb.append(i+1 + " ");//gen.nextInt(i+1) + 1 + " ");
//		}
//		INPUT = sb.toString();


		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//		Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){
//			@Override
//			public void run() {
//				long s = System.currentTimeMillis();
//				solve();
//				out.flush();
//				if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//			}
//		};
//		t.start();
//		t.join();
	}
	
	public static void main(String[] args) throws Exception { new E2().run(); }
	
	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private long[] nal(int n)
	{
		long[] a = new long[n];
		for(int i = 0;i < n;i++)a[i] = nl();
		return a;
	}
	
	private char[][] nm(int n, int m) {
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[][] nmi(int n, int m) {
		int[][] map = new int[n][];
		for(int i = 0;i < n;i++)map[i] = na(m);
		return map;
	}
	
	private int ni() { return (int)nl(); }
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}
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