Poll & solutions

[elz]

First:

Poll #1689

Open to: Registered Users, detailed results viewable to: All, participants: 25

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Tickyboxes!

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Finished lecture 2
24 (96.0%)

Finished problem set 1
15 (60.0%)

Also, it occurs to me that it might be handy to have a place to post/discuss solutions to the problem sets, to see what we can learn from each other in the absence of TAs. If you actually go to MIT and the problem sets are still the same, don't read these. ;)

Fire away!

Comments

[ungemmed]

argh, Dreamwidth keeps on choking on my solution for problem 2! I guess it's reading the code as some malicious hacking attempt or something.

[badgerbag]

try wrapping it in

  or  tags maybe...

[ungemmed]

Thanks! It actually turned out, though, that NoScript was being overzealous and thought Dreamwidth was trying to hack me. o.O

[ungemmed]

Problem 2

import math

n = int(raw_input('n? '))

primes = [2]
x = 3
logs = 0
while x <= n:
    divisible = False
    root = math.sqrt(x)
    for y in primes:
        if x % y == 0:
            divisible = True
            break
        if y > root:
            break
    if not divisible:
        logs += math.log(x)
        primes.append(x)
    x += 2
print logs
print logs / n