## Search found 27 matches

Thu Jun 01, 2017 10:11 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 389
Replies: 17
Views: 5665

### Re: Problem 389

What numbers are written in each dice? I don't know even 1-indexed or 0-indexed.
Tue Sep 06, 2016 11:49 pm
Forum: News, Suggestions, and FAQ
Topic: Ordering by kudos
Replies: 7
Views: 1973

### Re: Ordering by kudos

Not problem 75. problem 39. it's so similar. sorry.
And problem 52 was given 5 kudos but it was deleted a few weeks ago.
That is, "You shouldn't erase non-permanent post which given many (ex. 5 or more) kudos. You should remain more good posts."
Tue Sep 06, 2016 1:42 am
Forum: News, Suggestions, and FAQ
Topic: Ordering by kudos
Replies: 7
Views: 1973

### Re: Ordering by kudos

I got 5 Kudos in problem 52 forum, but this thread was deleted a few weeks ago. I clicked "ordering by kudos" button and my thread is in the top 25 (it is also top 10), but it is not in the forum (because it is deleted). Do you have any idea about "non-permanent and given many kudos" post? Informati...
Tue Aug 16, 2016 10:32 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 266
Replies: 14
Views: 5615

### Re: Problem 266

Thanks, v6ph1!
I realized that my code had been overflowed...
Finally I got AC
Tue Aug 16, 2016 8:01 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 266
Replies: 14
Views: 5615

### Re: Problem 266

I got Wrong Answer in my program. Let f(n) = (the answer where p = (product of primes below n) ). (after taking mod) f(30) = 79534 f(50) = 783152070 f(70) = 2803119896185 f(100) = 840xxxxxxxxxx365 (16 digits) f(150) = 60xxxxxxxxxx310 (15 digits) f(190) = 884xxxxxxxxxx635 (16 digits) What value is wr...
Fri Jul 15, 2016 9:05 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 089
Replies: 67
Views: 21195

### Re: Problem 089

You said "I entered 5000 into the roman numeral converter, so it was an invalid number". But, It is written under the converter, in the list of roman numerals. This page written: $5000 = \bar{V}$, $10000 = \bar{X}$, $50000 = \bar{L}$, $100000 = \bar{C}$, $500000 = \bar{D}$, and $1000000 = \bar{M}$. ...
Fri Jul 15, 2016 4:35 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 089
Replies: 67
Views: 21195

### Re: Problem 089

I think $5000 = \bar{V}$. It's written in this page.

So, $4900 = MMMMCM = C \bar{V}$.

Is this problem says 4900 can represent only 2 characters?
Fri Jul 15, 2016 3:11 am
Forum: Combinatorics
Topic: Do you have any efficient algorithm?
Replies: 8
Views: 7999

### Re: Do you have any efficient algorithm?

It's able to calculate factorials and binomial coefficients in hundreds of milliseconds with this algorithm.
Fri Jul 08, 2016 10:35 am
Forum: Combinatorics
Topic: Do you have any efficient algorithm?
Replies: 8
Views: 7999

### Re: Do you have any efficient algorithm?

I improved this solution and it is the fast $O(n)$ algorithm. This is my C++ code: #include <iostream> using namespace std; int modpow(int a, int b, int m) { int ret = 1; for(int i = 30; i >= 0; i--) { ret = 1LL * ret * ret % m; if(b & (1 << i)) ret = 1LL * ret * a % m; } return ret; } int modinv(in...
Fri Jul 08, 2016 3:29 am
Forum: Combinatorics
Topic: Do you have any efficient algorithm?
Replies: 8
Views: 7999

### Re: Do you have any efficient algorithm?

We can prove that $1,000,000,006! \equiv 1,000,000,006 \text{ } (\text{mod } 1,000,000,007)$. So, if you want to calculate for big n, you can use mod inverse like this code: #include <iostream> using namespace std; int modpow(int a, int b, int m) { int ret = 1; for(int i = 30; i >= 0; i--) { ret = 1...
Thu Jul 07, 2016 10:48 am
Forum: Combinatorics
Topic: Do you have any efficient algorithm?
Replies: 8
Views: 7999

### Do you have any efficient algorithm?

I have a question:
You are given an integer n.
Find $n! \mod 1,000,000,007$.
I can calculate for $O(n)$ for a naive calculation.

But if $n \le 1,000,000,000$, I can't calculate for a few seconds.

Do you have an "efficient" algorithm?
Wed Jun 15, 2016 10:59 am
Forum: News, Suggestions, and FAQ
Topic: How to get Kudos?
Replies: 2
Views: 1131

### How to get Kudos?

Hello, everyone. I'm solving 151 problems and writing many posts in the problem forum. I want to get 10 Kudos in a thread and make "Guru Post". I got 3 to 6 Kudos in my "good" thread (of course it has "not good" thread), but I can't make a post that it gets 10 Kudos. Can anyone advise? Thank you for...
Sun Jun 05, 2016 4:54 am
Forum: News, Suggestions, and FAQ
Topic: Does/did anyone else hit a brick wall when getting to about 70-80 problems solved?
Replies: 8
Views: 3842

### Re: Does/did anyone else hit a brick wall when getting to about 70-80 problems solved?

I've been solving 149 problems, but it was difficult to climb over the "100-problems wall". But projecteuler has many easy problems (brute force etc.) . 92: Square digit chains 95: Amicable chains 99: Largest exponential 112. Bouncy numbers 145: How many reversible numbers are there below one-billio...
Thu May 26, 2016 10:17 am
Forum: Programming languages
Topic: New Preferred Programming Language Requests
Replies: 160
Views: 74457

### Re: New Preferred Programming Language Requests

Hello, I'm square1001.

I think Javascript is very popular programming language.

But actually, there is no "Javascript" in this programming language list.

Java and Javascript is different, so we should add in this list.

Sun May 15, 2016 12:35 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 512
Replies: 2
Views: 1579

### Problem 512

Is there any "memory usage is less than (int)*(500,000,000) (=1.86GB)" solution?
Thu May 05, 2016 12:41 pm
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 539
Views: 123033

### Re: Errors/Warnings/Bugs

Problem 205 Peter has nine four-sided (pyramidal) dice, each with faces numbered 1, 2, 3, 4. Colin has six six-sided (cubic) dice, each with faces numbered 1, 2, 3, 4, 5, 6. Peter and Colin roll their dice and compare totals: the highest total wins. The result is a draw if the totals are equal. What...
Thu May 05, 2016 6:03 am
Forum: News, Suggestions, and FAQ
Topic: Awards Question
Replies: 2
Views: 857

### Awards Question

Hello, everyone. I am enjoying projecteuler, and I wrote many problem thread. I have a question about Forum Post Awards. Wise Words's achievement is "Receive 5 Kudos for ALL your posts". I received 24 Kudos for all my posts, but I received only four Kudos in the permanent post. And the progress is 4...
Sun May 01, 2016 12:33 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 557
Replies: 1
Views: 1148

### Problem 557

Hello, everyone. I solved for $O(n^3)$ solution in $31$ minutes. I checked the thread and I think my solution and uwi's solution is same, but uwi is computed in $86$ seconds. I think 1-minute rule is unfair because computing speed is very different in different PC. What do you think? Please tell me.
Fri Apr 29, 2016 12:37 am
Forum: Resources
Topic: Japanese Translation
Replies: 0
Views: 7636

### Japanese Translation

This is the Japanese Translation page.

http://www.odz.sakura.ne.jp/projecteule ... ct%20Euler.