Activity for celtschk
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Question | — |
Multiply two strings Given two strings, I define their product as follows: If any of the two strings is empty, the product is the empty string. If the second string consists of a single character, the result is obtained by replacing every character of the first string that compares larger than that character ... (more) |
— | about 3 years ago |
| Comment | Post #283649 |
I just noticed that you put the encryption tag on this challenge. That is not appropriate; encryption means to encode a message so that only people with the correct decryption key can decode it. Decoding binary doesn't need a decryption key. (more) |
— | about 3 years ago |
| Comment | Post #283652 |
Actually I started with a loop containing a single printf statement (but no width specifications; just a lot of `%1$s` style stuff), but then found that putting the singular/plural logic into a separate function saves more space because I essentially repeated the same logic for `i-1` as I couldn't de... (more) |
— | about 3 years ago |
| Comment | Post #283649 |
If you don't care about negative integers, the best option would be to say that it may be assumed that the code is only called on non-negative integers. (more) |
— | about 3 years ago |
| Comment | Post #283649 |
What about negative integers? (more) |
— | about 3 years ago |
| Edit | Post #283652 | Initial revision | — | about 3 years ago |
| Answer | — |
A: 99 Shortened Bottles of Beer [C (gcc)], 232 bytes f(n,w,p){printf("%i bottle%s of beer%s%s",n,"s"+(n1?"Take one down and pass it around, ":"Go to the store and buy some more, ");f(--i?:99,0,".\n\n");}} Try it online! Main golfing techniques: The repetitive part has been put into a function conditiona... (more) |
— | about 3 years ago |
| Comment | Post #283649 |
You might want to restrict the input to disallow a “converter” that takes the number in binary and copies it to output unchanged. (more) |
— | about 3 years ago |
| Comment | Post #283649 |
Why does the integer have to be named n? (more) |
— | about 3 years ago |
| Edit | Post #283617 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Evaluate a single variable polynomial equation [C++ (gcc)], 61 bytes float f(int n,floatp,float x){return n?p+xf(n-1,p+1,x):0;} Try it online! (more) |
— | over 3 years ago |
| Edit | Post #283603 |
Post edited: Added that reversal of parameters is allowed if explicitly stated |
— | over 3 years ago |
| Comment | Post #283603 |
As long as you explicitly state that the second factor is passed in first, I'd consider that acceptable. I've edited the post accordingly. (more) |
— | over 3 years ago |
| Edit | Post #283603 |
Post edited: |
— | over 3 years ago |
| Edit | Post #283603 | Initial revision | — | over 3 years ago |
| Article | — |
Multiply two strings [FINALIZED] Given two strings, I define their product as follows: If any of the two strings is empty, the product is the empty string. If the second string consists of a single character, the result is obtained by replacing every character of the first string that compares larger than that character ... (more) |
— | over 3 years ago |
| Edit | Post #281721 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Golf a FRACTRAN interpreter [Python 3], 76 71 bytes Saved 5 bytes thanks to user def f(p,n):l=[np//q for(p,q)in p if n%q<1];return f(p,l[0])if l else n Try it online! This code assumes that the fractions are given as completely cancelled pairs of integers. (more) |
— | over 3 years ago |
| Comment | Post #279854 |
Figuring that out was intended to be part of the challenge? I would never have guessed *that.* The one single most important thing about a challenge is to be crystal clear on what is expected from a solution. Up to now, my comments were about things where people could be misled by reasonable assumpti... (more) |
— | almost 4 years ago |
| Comment | Post #279854 |
On the `{n}=2n`: That's just an observation/extrapolation from the examples given. But the order you describe implies `m<n => {m} < {n]`, which means that when `{5} > {6}` then your mapping does not respect your order. While there's of course not a requirement to respect the order, it is what I woul... (more) |
— | almost 4 years ago |
| Comment | Post #279854 |
According to the task description, the task is to return a string, not a set. I took it that your algorithm gives that string. So what you are saying is that the algorithm only gives *some* representation of the set, and the program has to then calculate the set from that representation, and then to ... (more) |
— | almost 4 years ago |
| Comment | Post #279854 |
Also, what number corresponds to the set `{{{}, {{{}}}}}` (that is, `{5}`)? Up to n=4, the sets {n} seem to have ascending numbers (`{0}=1`, `{1}=2`, `{2}=4`, `{3}=6`, `{4}=8`), but then the next single-element set is `{6}=12`. Indeed, from those examples, it seems that `{n}=2n`, but `10={1,3}≠{5}`. (more) |
— | almost 4 years ago |
| Comment | Post #279854 |
BTW, your algorithm produces strings without spaces, but your examples contain spaces after the commas. This raises the question of (a) whether those spaces should be generated, and (b) whether the code should handle such spaces and/or the absence of them in the input. (more) |
— | almost 4 years ago |
| Comment | Post #279854 |
Since all strings are of finite length, only hereditary finite sets can be represented as such strings anyway. And even if you consider strings of countably infinite length, you obviously cannot represent all sets as such strings. I think a better strategy would be to define the “set strings” by thei... (more) |
— | almost 4 years ago |
| Comment | Post #279854 |
I haven't completely gone through your algorithm, but I suspect what you define is the [Ackermann bijection](https://en.wikipedia.org/wiki/Hereditarily_finite_set#Ackermann%27s_bijection) between the natural numbers and the hereditary finite sets. (more) |
— | almost 4 years ago |
| Comment | Post #279854 |
Your depth is called rank (see [here](https://math.stackexchange.com/a/458305/34930)). Note that the definition you give only works for finite sets, as in infinite sets there may not be a maximum, see the link for a definition that always works. Also, what you call “finite” is properly called heredit... (more) |
— | almost 4 years ago |
| Edit | Post #279820 | Post edited | — | almost 4 years ago |
| Suggested Edit | Post #279820 |
Suggested edit: This is not kolmogorov-complexity, as it takes input (more) |
helpful | almost 4 years ago |
| Comment | Post #279722 |
This is not kolmogorov-complexity, as it takes input. (more) |
— | almost 4 years ago |
| Comment | Post #279791 |
An explanation would be nice. (more) |
— | almost 4 years ago |
| Edit | Post #279790 | Initial revision | — | almost 4 years ago |
| Question | — |
Generate Lewis Caroll's Jabberwocky The task is to generate the text of Lewis Caroll's Jabberwocky. The text, quoted from Wikipedia, is as follows (I've replaced a non-ASCII character with ASCII, otherwise it's direct copy&paste from the linked Wikipedia article): ``` 'Twas brillig, and the slithy toves Did gyre and gimble in t... (more) |
— | almost 4 years ago |
| Edit | Post #279666 |
Post edited: |
— | almost 4 years ago |
| Comment | Post #279253 |
@Razetime: You should probably add that as a test case, as several currently posted solutions fail in this case. (more) |
— | almost 4 years ago |
| Edit | Post #279706 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: Length of a Sumac Sequence [C (gcc)], 32 bytes f(a,b){return a>0?f(b,a-b)+1:0;} Try it online! (more) |
— | almost 4 years ago |
| Comment | Post #279253 |
What should be the result for t1=t2=0? (more) |
— | almost 4 years ago |
| Edit | Post #279666 | Initial revision | — | almost 4 years ago |
| Article | — |
Generate Lewis Caroll's Jabberwocky [FINALIZED] The task is to generate the text of Lewis Caroll's Jabberwocky. The text, quoted from Wikipedia, is as follows (I've replaced a non-ASCII character with ASCII, otherwise it's direct copy&paste from the linked Wikipedia article): ``` 'Twas brillig, and the slithy toves Did gyre and gimble in t... (more) |
— | almost 4 years ago |
| Edit | Post #279629 |
Post edited: I forgot to replace some variable names in the ungolfed version; also improved formatting of that version slightly |
— | almost 4 years ago |
| Edit | Post #279629 |
Post edited: ungolfed/commented version |
— | almost 4 years ago |
| Edit | Post #279629 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: Given the preorder and the inorder of a tree, output the postorder [C (gcc)], 114 bytes f(int n,intp,inti,into){if(n){intm=i,k;for(;m!=p;++m);k=m-i;f(k,p+1,i,o);f(n-k-1,p+k+1,m+1,o);(o)++=p;}} Try it online! Arguments: `n` is the length of the arrays `p` is the preorder array `i` is the inorder array `o` is a pointer to a pointer t... (more) |
— | almost 4 years ago |
| Comment | Post #279425 |
You can save 7 bytes by replacing `'SIGSEGV'` with `11` (the signal number of SIGSEGV). (more) |
— | almost 4 years ago |
| Comment | Post #279141 |
Is it intentional that this community is not listed on the [main page?](https://codidact.com/) (I already commented about that on the proposal post, but I guess that was the wrong place for that comment) (more) |
— | about 4 years ago |
| Edit | Post #279407 | Initial revision | — | about 4 years ago |
| Article | — |
Run-length encode a byte sequence [FINALIZED] Run-length encoding is a simple compression technique which compresses sequences of repeating identical bytes. The encoding rules for this task are as follows: Any sequence of $n$ identical bytes ($3 \leq n \leq 63$) is replaced by a byte with value `n+0xc0` followed by only one copy of that by... (more) |
— | about 4 years ago |
| Edit | Post #279383 |
Post edited: Added ungolfed version of the code with explanation in the comments |
— | about 4 years ago |
| Edit | Post #279383 | Initial revision | — | about 4 years ago |
| Answer | — |
A: 1, 2, Fizz, 4, Buzz! C (gcc), 113 Bytes ``` i;main(){while(i++ / Declare a global int variable. The golfed code omits the type because of the old implicit-int rule, which only generates a warning also in modern gcc. Also note that global variables without initializer are zero-initialized; this is sti... (more) |
— | about 4 years ago |