"""

Solution to the birthday exercise
Think Python
Allen B. Downey

"""

import random

def has_duplicates(t):
    """return True if any element appears more than once in (t),
    False otherwise"""
    s = t[:]
    s.sort()
    for i in range(len(s)-1):
        if s[i] == s[i+1]:
            return True
    return False

def random_bdays(n):
    """return a list of integers between 1 and 365, with length (n)"""
    t = []
    for i in range(n):
        bday = random.randint(1, 365)
        t.append(bday)
    return t

def count_matches(students, samples):
    """generates (samples) samples of (students) students, and count
    how many of them have at least one pair of students with the same bday"""
    population = range(1, 35)
    count = 0
    for i in range(samples):
        t = random_bdays(students)
        if has_duplicates(t):
            count += 1
    return count

"""run the birthday simulation 1000 times and print the number of matches"""
x = count_matches(23, 1000)
print x