結果

問題 No.76 回数の期待値で練習
コンテスト
ユーザー uwi
提出日時 2014-11-24 05:24:23
言語 Java
(openjdk 23)
結果
AC  
実行時間 1,036 ms / 5,000 ms
コード長 4,832 bytes
コンパイル時間 3,046 ms
コンパイル使用メモリ 82,504 KB
実行使用メモリ 217,752 KB
最終ジャッジ日時 2025-01-02 21:08:50
合計ジャッジ時間 4,152 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge3
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ファイルパターン 結果
other AC * 2
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ソースコード

diff #
raw source code 

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 Main {
	static InputStream is;
	static PrintWriter out;
	static String INPUT = "";
	
	static double[] es = {
			1.0000000000000000,
			1.0833333333333333,
			1.2569444444444444,
			1.5353009259259260,
			1.6915991512345676,
			2.0513639724794235
	};
	
	static void solve()
	{
		double[] xi = new double[7];
		for(int i = 1;i <= 5;i++){
			double low = 0, high = 1;
			for(int rep = 0;rep < 100;rep++){
				double h = (low+high)/2;
				xi[i] = h;
				double rem = 1;
				for(int j = 1;j <= i;j++)rem -= xi[j];
				double[] p = new double[i+1+7];
				double[] e = new double[i+1+7];
				p[0] = 1;
				for(int k = 0;k < i+1;k++){
					for(int l = 1;l <= i;l++){
						p[k+l] += p[k] * xi[l];
						e[k+l] += e[k] * xi[l] + p[k] * xi[l];
					}
					p[k+6] += p[k] * rem;
					e[k+6] += e[k] * rem + p[k] * rem;
				}
				double ee = 0;
				for(int u = i+1;u < e.length;u++){
					ee += e[u];
				}
				if(ee > es[i]){
					high = h;
				}else{
					low = h;
				}
			}
		}
		xi[6] = 1-xi[1]-xi[2]-xi[3]-xi[4]-xi[5];
		tr(xi);
		
		for(int T = ni();T >= 1;T--){
			int n = ni();
			double[] e = new double[n+6];
			double[] p = new double[n+6];
			// e(x)=(e(x-6)+..+e(x-1))/6+p(x)
			// p(x)=(p(x-6)+..+p(x-1))/6
			e[0] = 0; p[0] = 1;
			for(int i = 0;i < n;i++){
				for(int j = i+1;j <= i+6;j++){
					p[j] += p[i] * xi[j-i];
					e[j] += e[i] * xi[j-i] + p[i] * xi[j-i];
				}
			}
			double ret = 0;
			for(int k = n;k < n+6;k++){
				ret += e[k];
			}
			out.printf("%.12f\n", ret);
		}
	}
	
	public static void main(String[] args) throws Exception
	{
		long S = System.currentTimeMillis();
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		solve();
		out.flush();
		long G = System.currentTimeMillis();
		tr(G-S+"ms");
	}
	
	private static boolean eof()
	{
		if(lenbuf == -1)return true;
		int lptr = ptrbuf;
		while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;
		
		try {
			is.mark(1000);
			while(true){
				int b = is.read();
				if(b == -1){
					is.reset();
					return true;
				}else if(!isSpaceChar(b)){
					is.reset();
					return false;
				}
			}
		} catch (IOException e) {
			return true;
		}
	}
	
	private static byte[] inbuf = new byte[1024];
	static int lenbuf = 0, ptrbuf = 0;
	
	private static 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 static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private static double nd() { return Double.parseDouble(ns()); }
	private static char nc() { return (char)skip(); }
	
	private static 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 static 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 static 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 static int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private static int ni()
	{
		int num = 0, 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 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) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }
}
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