The answer to 'The Birthday Problem'

birthdayProblem.coffee

randomBirthdays = (n) ->
    r = {}
    for i in [1..n]
        r[Math.floor Math.random() * 364 + 1] = true
    k for k,v of r

do ->
    n = 23; sum = 0
    for i in [0..Math.pow 10, 4]
        if n != (randomBirthdays n).length
            sum++
    console.log sum/i