#301861 (Java21) No.758 VVVVV

提出ソース

結果

問題	No.758 VVVVV
ユーザー	uwi
提出日時	2018-12-06 00:15:59
言語	Java21 (openjdk 21)
結果	AC
実行時間	166 ms / 2,000 ms
コード長	5,539 bytes
コンパイル時間	4,417 ms
コンパイル使用メモリ	85,068 KB
実行使用メモリ	47,048 KB
最終ジャッジ日時	2024-10-14 01:46:10
合計ジャッジ時間	8,020 ms
ジャッジサーバーID （参考情報）	judge5 / judge3

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	61 ms 37,604 KB
testcase_01	AC	61 ms 37,996 KB
testcase_02	AC	59 ms 38,112 KB
testcase_03	AC	150 ms 46,956 KB
testcase_04	AC	110 ms 40,772 KB
testcase_05	AC	102 ms 40,564 KB
testcase_06	AC	100 ms 40,020 KB
testcase_07	AC	156 ms 46,836 KB
testcase_08	AC	114 ms 41,456 KB
testcase_09	AC	96 ms 39,528 KB
testcase_10	AC	102 ms 40,828 KB
testcase_11	AC	157 ms 47,048 KB
testcase_12	AC	98 ms 40,308 KB
testcase_13	AC	100 ms 40,564 KB
testcase_14	AC	91 ms 39,900 KB
testcase_15	AC	89 ms 39,524 KB
testcase_16	AC	89 ms 39,848 KB
testcase_17	AC	155 ms 45,740 KB
testcase_18	AC	108 ms 40,924 KB
testcase_19	AC	165 ms 46,764 KB
testcase_20	AC	100 ms 40,176 KB
testcase_21	AC	101 ms 40,272 KB
testcase_22	AC	166 ms 46,876 KB
testcase_23	AC	61 ms 38,152 KB
testcase_24	AC	60 ms 38,012 KB
testcase_25	AC	59 ms 37,864 KB

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ソースコード

raw source code

package adv2018;
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 Day6 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = 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[][] fif = enumFIF(100005, mod);
		
		if(n == 1) {
			out.println(1);
			return;
		}
		
		int m = 0;
		for(int i = 1;i < n;i++) {
			if(g[i].length == 1)m++;
		}
//		m = 2*m-1;
//		n = 2*n-2;
		n--;
		out.println(C(n-1, m-1, mod, fif) * C(n, m-1, mod, fif) % mod * invl(m, mod) % mod);
//		
		// 1 3 1
		// 1 6 6 1
//		int n = 4*2-2;
//		int mod = 1000000007;
//		int m = 5;
//		long[][][][] dp = new long[n+1][m+1][100][2];
//		dp[0][0][0][0] = 1;
//		
//		for(int i = 0;i < n;i++) {
//			for(int j = 0;j <= m;j++) {
//				for(int h = 0;h < 100;h++) {
//					for(int p = 0;p < 2;p++) {
//						for(int q = 0;q < 2;q++) {
//							int nh = h+(q == 0 ? 1 : -1);
//							if(nh >= 100 || nh < 0)continue;
//							if(p == q) {
//								dp[i+1][j][nh][q] += dp[i][j][h][p];
//							}else {
//								if(j+1 <= m) {
//									dp[i+1][j+1][nh][q] += dp[i][j][h][p];
//								}
//							}
//						}
//					}
//				}
//			}
//		}
//		tr(dp[n][m][0][0] + dp[n][m][0][1]);
	}
	
	public static long invl(long a, long mod) {
		long b = mod;
		long p = 1, q = 0;
		while (b > 0) {
			long c = a / b;
			long d;
			d = a;
			a = b;
			b = d % b;
			d = p;
			p = q;
			q = d - c * q;
		}
		return p < 0 ? p + mod : p;
	}


	public static int[][] enumFIF(int n, int mod) {
		int[] f = new int[n + 1];
		int[] invf = new int[n + 1];
		f[0] = 1;
		for (int i = 1; i <= n; i++) {
			f[i] = (int) ((long) f[i - 1] * i % mod);
		}
		long a = f[n];
		long b = mod;
		long p = 1, q = 0;
		while (b > 0) {
			long c = a / b;
			long d;
			d = a;
			a = b;
			b = d % b;
			d = p;
			p = q;
			q = d - c * q;
		}
		invf[n] = (int) (p < 0 ? p + mod : p);
		for (int i = n - 1; i >= 0; i--) {
			invf[i] = (int) ((long) invf[i + 1] * (i + 1) % mod);
		}
		return new int[][] { f, invf };
	}
	
	public static long C(int n, int r, int mod, int[][] fif) {
		if (n < 0 || r < 0 || r > n)
			return 0;
		return (long) fif[0][n] * fif[1][r] % mod * fif[1][n - r] % mod;
	}


	static int[][] packU(int n, int[] from, int[] to) {
		int[][] g = new int[n][];
		int[] p = new int[n];
		for (int f : from)
			p[f]++;
		for (int t : to)
			p[t]++;
		for (int i = 0; i < n; i++)
			g[i] = new int[p[i]];
		for (int i = 0; i < from.length; i++) {
			g[from[i]][--p[from[i]]] = to[i];
			g[to[i]][--p[to[i]]] = from[i];
		}
		return g;
	}

	
	void run() throws Exception
	{
		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 Day6().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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結果

テストケース

ソースコード