Question

Hey, I'm having trouble with problem set 1, question 1. The program runs so the problem is obviously in my semantics but I am not sure how to correct it. If some one could point me in the right direction, that would be greatly appreciated. Here's my attempt. Thanks

x = 1000
initial = 10
pc = 4
if initial/1==initial and initial/2 != initial and initial/3 != initial and initial/5 != initial and initial/7 != initial:
while pc <= x:
initial = initial + 1
pc = pc + 1
print initial
else: initial=initial +1

Answer 1

okay. I ran this, and the first 2 numbers I got are 11 then 12. 12 in not a prime number. 12 can be divided by 2. But 12 divided by 2 is not 12 (initial/2!=initial)so the conditions are met for the if statement.

To fix this, think about the use of '%'

However, even if you fix the issue in the conditions, you will still have problems. What happens if a number is divided by only larger numbers than 7?

Answer 2

also, try out dpaste.com

It is much preferred than posting code direct.

Answer 3

I don't think you can write this program given the tools you have at the start without creating some kind of loop to walk through.

Answer 4

I agree, it would be better is you read more about iteration and loops, the for loop is actually very important in the first program. I would recommend reading through the python tutorial under the readings section. This is a program i modified from an example i found on there.

PrimesCount=0
Number=2
while PrimesCount <1000:
while (Number >= 2):
for x in range(2, n):
if n % x == 0:
n=n+1
break
else:
# loop fell through without finding a factor
print n, 'is a prime number'
Primes = Primes + 1
n=n+1
break

Answer 5

oh here is the dpaste link
http://dpaste.com/581166/