SUNDAY CHALLENGE

Question

Find the numbers < N that can be expressed as a sum of two cubes in TWO ways.

Optimize your program so that N can be as big as possible.

ex: 1729=12^3+1^3=9^3+10^3

Congrats to Sayan for winning this ! I encourage you to read the story that led to this challenge : http://mathworld.wolfram.com/Hardy-RamanujanNumber.html

Answer 1

max limit it can go up to 400000 (400 K)
VERSION--iii
in cpp or java it can cross 800000 or even more i think..
https://code.sololearn.com/cQ0HxhBX6xuL/?ref=app

Answer 2

Nice one.
Working on..

Answer 3

https://code.sololearn.com/c0OZbtGoZ2cV/?ref=app

can go up to 750 000

Answer 4

heres mine
enter maximun limit
its beta version..
will get more efficient i hope...

can work upto max limit--90000
just input the max limit

https://code.sololearn.com/cCO912F1Ak7P/?ref=app

Answer 5

Can it be n = 2*i^3 ?

Answer 6

two ways means
give an eg

Answer 7

@ sayantan
your program
dont checks if its a dobule cube pair..
like...
i^3 + j^3 = n = k^3 + l^3
it must be dobule
and
same pairs cant be there
like...
i^3 + j^3 = n = j^3 + i^3

Answer 8

@sayan example: 1729=12^3+1^3=9^3+10^3

Answer 9

Ok who will find the highest number ?

Answer 10

There are MANY more... Python is not great for memiry management. But with a few tricks you can go much higher

Answer 11

No. But the higher from this thread yes :-)

Answer 12

No - needs to be different ways

Answer 13

@Baptiste Best so far but can you do even better ?

Answer 14

Ok @sayan wins this one, congratulations... But have a look at this version, especially the method to reduce memory use and go to higher Ns, here n=130000000 (not totally doable with python because its memory management is greedier)
https://code.sololearn.com/cDiR0xoxjm7y/?ref=app

Answer 15

Python version. Works up to x=10000000
https://code.sololearn.com/cB5SFl6S4T7A/?ref=app

Answer 16

here is new challenge...

https://www.sololearn.com/discuss/664933/?ref=app

Answer 17

TRY THIS BRAND NEW CHALLENGE AND GET FRESH..

https://www.sololearn.com/discuss/666260/?ref=app

Answer 18

HERE_IS_MY_NEW_CHALLENGE...
GET##FRESH##CHECK-IT-OUT

https://www.sololearn.com/discuss/668821/?ref=app