Project Euler Forum

It's me or lately PE problems became more and more difficult?

257 was hardest ever for me, 258 almost and 259 was not so easy...

Taifu wrote:It's me or lately PE problems became more and more difficult?

257 was hardest ever for me, 258 almost and 259 was not so easy...

Hrmm... while I'll agree that 257 & 258 were really difficult, it was mostly because I wasn't familiar with the most common methods people used to solve the problems (therefore frustrating).

That being said, I must severely disagree with you on 259. That one was damn near trivial, but I think it's nice for beginners to have good wading in problems in the higher set too, as I think the later half of problems are much more clever & interesting to learn.

It's because all these problems become easier after you've solved them, especially a long time ago. For example 156 looks very easy to me now but when I first tried it it was very very hard. And it's also relative, no need to elaborate on that ..

259 seems to me genuinely impossible to do in under a minute. I'm amazed that so many people have solved it so quickly - I think a few people solved it after just 10 minutes! But it's not so hard, I think, to do if you stretch the one minute rule a bit , and it's more about programming anyway. I will try to work on it now.

By the way: hard problems are GOOD. More satisfaction to solve, more challenge. If you solved the easy problems than go for the harder ones; if you have not yet, do them first than go for the latest.

Speaking of 259 I have a question, does the number '123456789' count as reachable ??

zwuupeape wrote:Speaking of 259 I have a question, does the number '123456789' count as reachable ??

From the problem description "Each operation can be used any number of times, or not at all."

quilan wrote:

Taifu wrote:It's me or lately PE problems became more and more difficult?
257 was hardest ever for me, 258 almost and 259 was not so easy...

Hrmm... while I'll agree that 257 & 258 were really difficult, it was mostly because I wasn't familiar with the most common methods people used to solve the problems (therefore frustrating).

That being said, I must severely disagree with you on 259. That one was damn near trivial, but I think it's nice for beginners to have good wading in problems in the higher set too, as I think the later half of problems are much more clever & interesting to learn.

Perhaps you are right infact I code it more or less right in less than one hour. But I spent about 10 hours trying to polish my python code (huge memory requirement and no less the 300 seconds).

Ciao.
Marco.

zwuupeape wrote:By the way: hard problems are GOOD. More satisfaction to solve, more challenge. If you solved the easy problems than go for the harder ones; if you have not yet, do them first than go for the latest.

I never told I hate them

Well, I hate them before solving them!

Taifu wrote:It's me or lately PE problems became more and more difficult?

I feel so since about 50 problems ...

Taifu wrote:Perhaps you are right infact I code it more or less right in less than one hour. But I spent about 10 hours trying to polish my python code (huge memory requirement and no less the 300 seconds).

Hrmm, my code runs in 69 seconds on my work PC, which is close enough for me (110s @ home). Does it take that much longer for you?

quilan wrote:

Taifu wrote:Perhaps you are right infact I code it more or less right in less than one hour. But I spent about 10 hours trying to polish my python code (huge memory requirement and no less the 300 seconds).

Hrmm, my code runs in 69 seconds on my work PC, which is close enough for me (110s @ home). Does it take that much longer for you?

I just tried it (using my gcd, but I don't think it's much different):
Total: ARGH!!! [sorry!]
Time taken: 110.823790s

So, you supposition is right: my code could be better

Ciao.
Marco.

Taifu wrote: I just tried it (using my gcd, but I don't think it's much different):
Total: <Solution>
Time taken: 110.823790s

So, you supposition is right: my code could be better

Ciao.
Marco.

Err, you might want to hide that solution.

genious999 wrote:

Taifu wrote: I just tried it (using my gcd, but I don't think it's much different):
Total: <Solution>
Time taken: 110.823790s

So, you supposition is right: my code could be better

Ciao.
Marco.

Err, you might want to hide that solution.

UOPS!!!! I thought I were in private forum.

Sorry and thank you.

genious999 wrote:

Taifu wrote: I just tried it (using my gcd, but I don't think it's much different):
Total: <Solution>
Time taken: 110.823790s

So, you supposition is right: my code could be better

Ciao.
Marco.

Err, you might want to hide that solution.

Hah! Nice.

Edit: Also, I personally LOVE the hardest problems, because nothing's more enjoyable (to me) than spending a week or two working on a solution & slowly whittling down the time from infinite or so, to around a minute. That's why I enjoyed immensely doing my own thing for 258 (and getting it down to a mildly respectable time), and then doing it again with other methods to get it under 25s.

What the heck ... How??

I've been trying to solve this problem. I don't know what kind of heuristics you use but merely generating the sets of numbers to work with without even doing any arithmetic operations on them, i.e {321, 45678, 9}, {1243567, 89} {2,1,3,4,6,5,8,9,7} etc, (Nice idea for problem, by the way, to enumerate them ...) takes like 6 minutes on my computer, and that's after every possible optimization... I managed to do only with combinations of any 7 digits out of 9 but nothing higher than that before I get MemoryError ..

this problem is anything but trivial ...

EDIT: Mark the part the digits have to be in order in red =\. Got it now.

zwuupeape wrote:What the heck ... How??

I've been trying to solve this problem. I don't know what kind of heuristics you use but merely generating the sets of numbers to work with without even doing any arithmetic operations on them, i.e {321, 45678, 9}, {1243567, 89} {2,1,3,4,6,5,8,9,7} etc, (Nice idea for problem, by the way, to enumerate them ...) takes like 6 minutes on my computer, and that's after every possible optimization... I managed to do only with combinations of any 7 digits out of 9 but nothing higher than that before I get MemoryError ..

this problem is anything but trivial ...

"Uses the digits 1 through 9, in that order and exactly once each."

This makes it trivial, and invalidates two of your three examples...

Edit: Nevermind, I see you got it.

To my opinion the problems are getting more and more difficult. Now, after nearly two years taking part in Project Euler, I am sorry to give it up because the puzzles are too difficult for me.

Too difficult? Whatever was your reason for joining then? The challenge should push you to learn new things and acquire skills, like they did for me!

The question was if the problems are increasingly difficult. To my opinion they are.
I spent more and more time trying problems without a result, so that they are now too challenging for me, not in general. Nevertheless I learned a lot by Project Euler.

In my opinion the first 140 or so problems are less difficult than the later problems (on average!). After 140 the difficulty of any 10 consecutive problems is more or less the same (a very hard one, a few easy ones, etc)

In my experience, newer problems seem a bit harder, because I try to solve them as fast as possible, (because I always try to get the first forum post ). Trying to solve a problem as quickly as possible usually doesn't make a problem any easier

Hopefully you are right. However, I will relax from PE and perhaps try again in some years.