Prime generator

[nvivek]

My script works fine in my computer.
But when i submit my code ,the result which i get is WRONG ANSWER...
Can anyone help me with that

[numerix]

You have to post your code, if you want others to find out why it produces WA.

[nvivek]

def prime():
    n=input("enter the number of cases")
    i=0
    ou=[]
    for i in range(n):
        print "enter the upper limit and lower limit"
        a=input()
        b=input()
        ou.append(a)
        ou.append(b)
    i=0
    j=0
    print "\n"
    while(i<len(ou)):
        for x in range(ou[i], ou[i+1]+1):
            if x==2:
                print x
            elif x!=1:
                for y in range(1, x+1):
                    if x%y==0:
                        j+=1
            if(j==2):
                print x
            j=0
        print "\n"
        i+=2

[macobo]

First obvious thing (but perhaps not the only one) is that you print other stuff besides the result.
DON'T DO THAT. The SPOJ server only accepts submittions that have exactly the expected output.

[numerix]

Apart from your algorithm you're missing the basics! As one can see from your submission list https://www.spoj.pl/status/nvivek16/ you did not even get "problem" TEST AC.
You should start here: https://www.spoj.pl/forum/viewtopic.php?f=20&t=49 and learn from that how to do the I/O on SPOJ.

If you understood that, you can care about your PRIME1-algorithm.
Try e.g. the intervall "999900000 1000000000" and look what your program does ...

[nvivek]

Thanks for ur reply...
But when i tried using raw_input...
I am getting WA...
What can i do?
Is there any error in my code..
I can run this code in my python IDE and i can get the exact output...
what changes should i make to run this in SPOJ?
I am new to spoj..So pl help

[numerix]

Let me repeat:
You should start here: https://www.spoj.pl/forum/viewtopic.php?f=20&t=49 and learn from that how to do the I/O on SPOJ.
If you are also new to Python: http://docs.python.org/release/2.6.6/library/index.html

[ielberd]

i still cant understand, anyone can tell where did i wrong?

t=input()
if t<=10:
	d=[[[0],[0]]]
	for s in range(t-1):
		d=[[[0],[0]]]+d
	for i in range(t):
		m,n = raw_input().split()
		d[i][0]=int(m)
		d[i][1]=int(n)
	for k in range(t):
		print ""
		if d[k][1]-d[k][0]>100000:
			break
		else:
			for j in range(d[k][0],d[k][0]+(d[k][1]-d[k][0])+1):
				p=0
				for o in range(1,j):
					if j%o==0:
						p=p+1
				if p==1:
					print j

[mihaibogdan11]

I think I'm losing my mind here.
I tried this first:

import math
def BinarySearch(l, r, x):
	global prime
	mij = (l + r) / 2
	if prime[mij] == x: return true
	elif l > r : return false
	elif prime[mij] > x : return BinarySearch(l, mij - 1, x)
	else : return BinarySearch(mij + 1, r, x)
casesNo = int(raw_input())
prim = [1] * 10001
for i in range(2, 10000): 
	if prim[i]:
		y = 2 * i 
		while (y <= 10000):
			prim[y] = 0
			y +=i
prime = []
for i in range(2, 10000):
	if prim[i]:
		prime += [i]
lng = len(prime)
while casesNo:
	interval = raw_input()
	i = interval.index(" ")
	a = int(interval[:i])
	a = max(a, 2)
	b = int(interval[i:])
	casesNo -= 1
	for x in range(a, b+1):
		if x > 10000:
			squareRoot = int(math.sqrt(x))
			for y in range(0,len(prime)):
				if prime[y] > squareRoot: break
				if x % prime[y] == 0: break
			if y + 1 == len(prime) or prime[y] > squareRoot:
				print x
		else:
			if BinarySearch(0, len(prime),x): print x

But It TLEed on me.
Then I even replaced erathosthene's with an actual list of prime constants, up to 50000!!!
Still TLE ...

How did you people managed this one?