Question

Can someone please review my ps1b? I'd appreciate any feedback.


import math

def isPrime(num):
if num > 1:
if num == 2:
return 1
i = 2
while i < math.sqrt(num) + 1:
if num%i == 0:
return 0
else:
i += 1
return 1
else:
return 0

def ps2(num):
i = 2
j = 0
logsum = math.log(2)
while j < num:
if isPrime(i) == 1:
j += 1
logsum += math.log(i)
if j == num:
print "N: ",num
print "Sum of logs: ",logsum
print "Ratio: ",num/logsum
i = i + 1

ps2(input("Enter a number: "))

Answer 1

sorry function ps2 should be called something like printLogInfo

Answer 2

2 problems.

1) The ratio should be the (sum of logs not including the nth prime)/the nth prime. In your problem, you divide 1000 by the sum of logs including the nth prime. This is wrong.

2) Note that you must not include the math.log(7919) in your Sum. The sum should be close to 7803 I believe.

3) I checked your problem. You add math.log(2) twice in your problem. Remove one to get 7803.3 which is the correct answer.

Answer 3

Thanks!