Re: [Tutor] OverflowError in lucky numbers script
I tried optimizing everything all things you guys pointed out and still its orders of magnitude away from the expected result. The program should check the islucky condition between range of (1,10**18) numbers and iterate over that 10**5 times. This program slows down more than 16 secs at (1,10**8) and 1 time. Which approach should i follow? ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] OverflowError in lucky numbers script
I have given the definition of lucky numbers and constraints involved at the starting of the thread. when a number's sum of digits and square of sum of digits is prime,it is called lucky. I already tried generating prime numbers using sieve of atkin algorithm rather than doing primality test. Efficiency improved a lot but still couldnt reach 16 sec target. The large numbers are the only hindrance to the speed. Since i m new to Python.I dont know all its recipes and tricks inlvolved to charm-the-snake. So can i improve the islucky method more than what i mentioned before? Can i work around that way in python or should i come up with a new algorithm? ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] OverflowError in lucky numbers script
No,i meant sum of digits is prime and also sum of square of digits is prime. E.g: 23 is lucky cos 2+3=5 (prime) 2**2+3**2 = 4+9 = 13 (prime) ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] OverflowError in lucky numbers script
I m using Python 2.7 Steven wrote: Scale your numbers from time to time, to avoid them getting too big What does this mean? inp refers to the sample input test case I have given at first.Its a string containing two numbers, The program has to handle large numbers till 10**18 and also has to execute considerably fast (within 16 CPU time). Using xrange() causes the OveflowError,Whereas using range() causes too many items Is writing my own generator only solution? Or is there another way in which i can generate big numbers and in considerably fast manner? ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] OverflowError in lucky numbers script
Calculating the table is fast. I think either my luckiness test (where i find the sum of all digits and sum of squares of all digits of a large number) or generating numbers is slow. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] OverflowError in lucky numbers script
Thank you all for helping me understand the overflow error.
I m a newbie on mailing lists.I apologize for my errors.
Program:
def sieve(maxi):
primes = range(2,maxi+1)
for i in primes:
j = 2
while i * j = primes[-1]:
if i * j in primes:
primes.remove(i*j)
j += 1
return primes
maxi=(10**2)*18 #Generating the table till the largest possible prime
tab=sieve(maxi)
table={}
for i in tab:
table[i]=0
def isprime(n):
return table.has_key(n)
count=0
def islucky(n): # modified islucky function
global count
sum1=0
sum2=0
for letter in str(n):
tmp=ord(letter)-48
sum1+=tmp
sum2+=tmp**2
if isprime(sum1):
if isprime(sum2):
count+=1
number=raw_input() # Number of test cases.Its constraint (1,1)
def execute():
global count
for i in range(int(number)):
inp=raw_input()# startnumber and endnumber pair. Its constraint
(1,10**18)
a=inp.split()
startnum=int(a[0])
endnum=int(a[1])
count=0
while startnum != endnum:
islucky(startnum)
startnum+=1
print count
execute()
The program is executing correctly but it has to execute 16 seconds for the
constraints.
I have optimized the way i sum up digits and used consult-table approach.
Still the program doesn't reach the 16 seconds target.
How to achieve this target?
___
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[Tutor] OverFlow Error
How to correct this error? * OverflowError: Python int too large to convert to C long* ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Tutor Digest, Vol 95, Issue 55
*Lucky Numbers* A number is called lucky if the sum of its digits, as well as the sum of the squares of its digits is a prime number. How many numbers between A and B are lucky? Input: The first line contains the number of test cases T. Each of the next T lines contains two integers, A and B. Output: Output T lines, one for each case containing the required answer for the corresponding case. Constraints: 1 = T = 1 1 = A = B = 10^18 Sample Input: 2 1 20 120 130 Sample Output: 4 1 Explanation: For the first case, the lucky numbers are 11, 12, 14, 16. For the second case, the only lucky number is 120. --- My solution: def isprime(n): n=abs(int(n)) if n2: return False if n==2: return True if not n 1: return False for x in range(3,int(n**0.5)+1,2): if n % x == 0: return False return True def islucky(n): sum1=0 sum2=0 while n!=0: r=n%10 sum1+=r sum2+=r*r n=n/10 if isprime(sum1) isprime(sum2): return True return False number=raw_input() for i in range(int(number)): inp=raw_input() a=inp.split() startnum=int(a[0]) endnum=int(a[1]) li=map(islucky,xrange(startnum, endnum)) count=0 for j in li: if j: count+=1 print count --- Traceback (most recent call last): File /run-1327085301-1965755690/solution.py, line 35, in li=map(islucky,xrange(startnum, endnum)) OverflowError: Python int too large to convert to C long --- It shows this error for very large numbers or slows down with large numbers. I m using Ubuntu 32-bit. On Sun, Jan 22, 2012 at 4:24 AM, tutor-requ...@python.org wrote: Send Tutor mailing list submissions to tutor@python.org To subscribe or unsubscribe via the World Wide Web, visit http://mail.python.org/mailman/listinfo/tutor or, via email, send a message with subject or body 'help' to tutor-requ...@python.org You can reach the person managing the list at tutor-ow...@python.org When replying, please edit your Subject line so it is more specific than Re: Contents of Tutor digest... Today's Topics: 1. OverFlow Error (Shreesh bhat) 2. Re: OverFlow Error (Alan Gauld) 3. Re: Tutor Digest, Vol 95, Issue 53 (George Nyoro) 4. Re: Tutor Digest, Vol 95, Issue 53 (Steven D'Aprano) 5. Re: delete an object from method (was Tutor Digest) (Dave Angel) 6. checking return status of 'ping' in windows (Nikunj Badjatya) 7. Re: checking return status of 'ping' in windows (Hugo Arts) -- Message: 1 Date: Sat, 21 Jan 2012 18:40:28 +0530 From: Shreesh bhat shreeshbha...@gmail.com To: tutor@python.org Subject: [Tutor] OverFlow Error Message-ID: ca+xjmj5mvbwqvbtwhnwo4_5+xpdd_pnv2c66m1+vm6w+a7t...@mail.gmail.com Content-Type: text/plain; charset=iso-8859-1 How to correct this error? * OverflowError: Python int too large to convert to C long* -- next part -- An HTML attachment was scrubbed... URL: http://mail.python.org/pipermail/tutor/attachments/20120121/f7b86624/attachment-0001.html -- Message: 2 Date: Sat, 21 Jan 2012 13:57:20 + From: Alan Gauld alan.ga...@btinternet.com To: tutor@python.org Subject: Re: [Tutor] OverFlow Error Message-ID: jfeg80$dh5$1...@dough.gmane.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed On 21/01/12 13:10, Shreesh bhat wrote: How to correct this error? * OverflowError: Python int too large to convert to C long* Could we have some context? What version of Python? What OS? What does your code look like? Can we see the full error trace please? Otherwise, based only on what you posted, the only advice I can give you is to use a smaller int! -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ -- Message: 3 Date: Sat, 21 Jan 2012 17:58:17 +0300 From: George Nyoro geony...@gmail.com To: tutor@python.org Subject: Re: [Tutor] Tutor Digest, Vol 95, Issue 53 Message-ID: CAM71YVE43XUXv5FmOvaXhL3Pv=-jvrvuoxehu-fqky08oeh...@mail.gmail.com Content-Type: text/plain; charset=iso-8859-1 Hey guys, I've been making an application and have made a delete method where the user can delete the instance of that application. e.g. if I have a table object, I need to be able to delete that instance from
