Question

what do you guys thin about for this answer for hw1 problem 1

Answer 1

def isprime(startnumber):
startnumber*=1.0
for divisor in range(2,int(startnumber/2)+1):
if startnumber/divisor==int(startnumber/divisor):
return False
return True
number=0
prime_counter=0
max_count=9001
while(prime_counter<max_count):
number=number+1
prime_counter=prime_counter
if isprime(number):
prime_counter=prime_counter+1
else:prime_counter=prime_counter

else:print number

Answer 2

ignore the max count of 9001, just testing larger numbers. it does produce the right answer with correct max count.

Answer 3

here is problem 2 of hw1

from math import *
def isprime(startnumber):
startnumber*=1.0
for divisor in range(2,int(startnumber*0.5)+1):
if startnumber/divisor==int(startnumber/divisor):
return False
return True

rawnumber=input('What number N to consider? ')
prime_sum_counter=0
number=0
while(number<rawnumber):
number=number+1.0
prime_sum_counter=prime_sum_counter
if isprime(number):
prime_sum_counter=prime_sum_counter+log(number)
else:prime_sum_counter=prime_sum_counter

else:print prime_sum_counter
print rawnumber
print prime_sum_counter/rawnumber

Answer 4

post your code using dpaste.com

Answer 5

problem 2:
for this line:
for divisor in range(2,int(startnumber*0.5)+1):
int(startnumber*0.5) can be expressed as startnumber/2

does this line work?
if startnumber/divisor==int(startnumber/divisor)
it looks like both sides of the comparison are the same
python does integer division - read this and look at the note in the table for the / operator
http://docs.python.org/library/stdtypes.html#numeric-types-int-float-long-complex

what is the purpose of the second line after your while statement
prime_sum_counter=prime_sum_counter

please use dpaste.com to post your code. It makes it easier for everyone. goto dpast.com - paste your code in the code block - select python for the syntax - click the paste it button - post the link here, thnx

put some print statements in your code and print variable values, comparison/calculation results, accumulator values ... stuff like that. It will help you see what your code is doing.

Answer 6

it works. the purpose of the prime_sum_counter= prime_sum_counter is to not alter the running sum if the number isn't prime.

Answer 7

also the function compares decimal to int so if they are equal it is a valid divisor

Answer 8

sorry - i missed that startnumber is a float