Birthday problem: Difference between revisions

Using simulation, estimate the number of independent people required in a groupsgroup before we can expect a ''better than even chance'' that at least 2 independent people in a group share a common birthday. Furthermore: Simulate and thus estimate when we can expect a ''better than even chance'' that at least 3, 4 & 5 independent people of the group share a common birthday. For simplicity assume that all of the people are alive...

<langsyntaxhighlight Adalang="ada">with Ada.Command_Line, Ada.Text_IO, Ada.Numerics.Discrete_random;

end Birthday_Test;</langsyntaxhighlight>

'''File: Birthday_problem.a68'''<langsyntaxhighlight lang="algol68">#!/usr/bin/a68g --script #

OD # group size #</langsyntaxhighlight>'''Output:'''

<langsyntaxhighlight lang="c">#include <stdio.h>

}</langsyntaxhighlight>

<langsyntaxhighlight lang="cpp">#include <iostream>

}</langsyntaxhighlight>

<langsyntaxhighlight lang="d">import std.stdio, std.random, std.algorithm, std.conv;

}</langsyntaxhighlight>

<langsyntaxhighlight lang="d">import std.stdio, std.random, std.math;

}</langsyntaxhighlight>

end.</langsyntaxhighlight>

<langsyntaxhighlight lang="go">package main

}</langsyntaxhighlight>

<langsyntaxhighlight lang="go">package main

}</langsyntaxhighlight>

<langsyntaxhighlight lang="lisp">(import

(print (birthday 5))</langsyntaxhighlight>

<langsyntaxhighlight Jlang="j">PopSmall=: 1e5 ?@# 365

)</langsyntaxhighlight>

<langsyntaxhighlight Jlang="j"> estGroupSz 2

313 0.500903</langsyntaxhighlight>

<langsyntaxhighlight lang="java">import static java.util.Arrays.stream;

}</langsyntaxhighlight>

<langsyntaxhighlight lang="julia">function equalbirthdays(sharers::Int, groupsize::Int; nrep::Int = 10000)

end</langsyntaxhighlight>

<langsyntaxhighlight lang="scala">// version 1.1.3

}</langsyntaxhighlight>

<langsyntaxhighlight Lassolang="lasso">if(sys_listunboundmethods !>> 'randomgen') => {

^}</langsyntaxhighlight>

<langsyntaxhighlight lang="parigp">simulate(n)=my(v=vecsort(vector(n,i,random(365))),t,c=1); for(i=2,n,if(v[i]>v[i-1],t=max(t,c);c=1,c++)); t

find(5)</langsyntaxhighlight>

<langsyntaxhighlight lang="perl">use strict;

printf "$_ people in a group of %s share a common birthday. (%.4f)\n", simulation($_) for 2..5</langsyntaxhighlight>

<span hi style="color: mid#008080;">else</span>

<langsyntaxhighlight PLlang="pl/Ii">*process source attributes xref;

End;</langsyntaxhighlight>

<langsyntaxhighlight lang="python">

print("%i independent people in a group of %s share a common birthday. (%5.1f)" % (sharers, groupsize, eq))</langsyntaxhighlight>

<langsyntaxhighlight lang="python">from collections import defaultdict

<langsyntaxhighlight lang="python"># ought to use a memoize class for all this

for x in range(2, 6): find_half(x)</langsyntaxhighlight>

<langsyntaxhighlight Racketlang="racket">#lang racket

sharers group-size (~r (* probability 100) #:precision '(= 2)))))</langsyntaxhighlight>

<syntaxhighlight lang="raku" perl6line>sub simulation ($c) {

printf "$_ people in a group of %s share a common birthday. (%.3f)\n", simulation($_) for 2..5;</langsyntaxhighlight>

<langsyntaxhighlight lang="rexx">/*REXX pgm examines the birthday problem via random# simulation (with specifiable parms)*/

end /*g*/ /*stick a fork in it, we're all done. */</langsyntaxhighlight>

<langsyntaxhighlight lang="rexx"> /*--------------------------------------------------------------------

End</langsyntaxhighlight>

<langsyntaxhighlight lang="ruby">def equalBirthdays(nSharers, groupSize, nRepetitions)

main()</langsyntaxhighlight>

<langsyntaxhighlight lang="tcl">proc birthdays {num {same 2}} {

}</langsyntaxhighlight>

<langsyntaxhighlight ecmascriptlang="wren">import "random" for Random

import "./fmt" for Fmt

}</langsyntaxhighlight>

<langsyntaxhighlight lang="zkl">fcn bdays(N){ // N is shared birthdays in a population

}</langsyntaxhighlight>