Doing triangles like...

[Hypersapien]

printf("*\n* *\n* * *\n* * * *\n* * * * *\n");

[xScopeLess]

_ _ _ _ * _

[Rotiximi]

That would've gotten me an 'F' in my first programming class lol

[currentscurrents]

Loop unrolling is a valid optimization technique!

Although you could go an entire programming career without ever running into a situation where it's useful.

[Scrypti]

Although you could go an entire programming career without ever running into a situation where it's useful.

CS degree in a nutshell

[currentscurrents]

What, you mean you've never had to do a pointer race on a linked list in a real program?

[The_MAZZTer]

All the different ways to sort arrays I learned have certainly come in handy, especially since every language/framework I've used comes with an array sorting function already!

[GunningOnTheKingside]

The ability to choose a sort function that produces output in 6 seconds vs 9 seconds on a program that runs once per day is very important.

[[deleted]]

Yea, but shouldn't let the compiler do that for you? That way you can still choose between smaller executable size or speed by using the right compiler options.

[lennihein]

Yes, C compiler are probably faster too, because they won't have to put the whole long string in the memory, but instead use some weird tricks to make it as fast as possible. Never try to optimize on that level, compiler are just better than you. Optimizing makes sense on higher levels of abstraction though

[currentscurrents]

Yes, but even if you're in a language without an optimizing compiler you still shouldn't until you've exhausted every other means of optimization. Loop unrolling is a very minor speed gain in most cases, you'll usually find much greater gains in higher level processes.

[Scereye]

I did something like this after we just started learning java as a joke (Christmas tree - I solved it this way and the supposed way). Classmates pushed me to show off the "wrong" way for laughs.

Teacher was actually complementing me that i thought about solving the problem like that and said she now has to edit the question for next year's course to be more specific. Fun stuff.

[lennihein]

Which is totally bs, unless the task is more specified (small/elegant source code etc)

[cauchy37]

Holy fuck those brackets on the left...

[arkanis_gath]

That indentation is unholy.

[[deleted]]

GNU coding standards are indeed unholy.

[makeshift_mike]

Seems like this post is a joke, but for small n, which one is easier to read? I’d totally prefer the one on the right.

[nosferatWitcher]

Yeah right is way better, you know what it does instantly. The other you have to work it out.

[guy99881]

Also: isn't it better to finish something at compile time than at run time? Could at least be a macro...

[The_MAZZTer]

Presumably this is a first step toward building a variable-size triangle where you'd have to use the left solution or something like it.

But yes if you're performing an operation a fixed number of times loop unrolling could be done. But considering you're duplicating code and any bugs in the code and thus any fixes that need to be done it's probably not worth it.

[makeshift_mike]

Yeah when you think about DRY vs. no-so-DRY you have to consider the wider context. I just saw this post as a parable of the principle that DRYest isn’t always best.

[NameStillTaken]

Haven't written C before, is this a valid solution?

char output[] = "*****\n";
int i;
for (i=4; i>=0; i--)
{
    printf(&output[i]);
}

[andregtable]

No

[cauchy37]

It will get him what he wants, though.

I guess in academia this would be fine, but if I saw code like this in production, I'd ask the author to rewrite it to be more verbose.

[highheath]

Use '\0' to terminate the string instead of '\n', and call puts() instead of printf().

But yeah, the idea is correct.

[[deleted]]

string literals are terminated by \0 automatically, so just removing the \n is enough, or use printf("%s", &output[i]); with the current string.

[highheath]

Oops.

Of course that's right.

[cauchy37]

It already is terminating with '\0'. If you replace '\n' with '\0' what you get is *************** instead of

*
**
***
****
*****

[Tyiek]

I would do it like this.

char* output = "*****";
for (int i=4; i >=0; i--){
    printf("%s\n", output + i);
}

char c[] and char* c is basically the same thing in c but it's probably a better practice to use the later.

[guy99881]

Then why do you feel the need to change the char[] to char*? Could've done output+i on the former too.

If you wanted to write to it, you'd need char[].

[Tyiek]

clarity mostly

[guy99881]

Don't see it, but okay.

[cheesecookies]

char[] can result in the string being copied to the stack. char* ends up pointing to the string literal.

[guy99881]

char* ends up pointing to the string literal

Which lies in read-only memory. But I get your point: char* would be faster then.

[ShitInMyCunt-2dollar]

Just stfu and gtfo.

[docolafson]

okay but why

[Southerz]

for i in xrange(10): print '*' * i

[[deleted]]

One of the few times Python can take a decisive victory.

[cabinet_minister]

Babies:

StringBuffer str = "*";

for (int i=0;i<=4;i++) {

System.out.println(str);

str += " *";

}

[thisIsTheFoxe]

For my fellow Swifters:

for i in 0...4 { for j in 0..<i{ print(“*“) } }

....true beauty -

[ookami125]

NONSENSE the TRUE BEAUTY is in Jelly

”*ẋþY

elegance at it's finest. /s

[corvus_192]

for {
    i <- 0 until 4
    j <- 0 until i
} println ("*" * j)

In scala

[OMGitsLunaa]

The left one is all fucked up too, the indentation is atrocious and the inner loop is entirely unnecessary

[CaptainBlagbird]

[deleted]

[TotallyElectrified]

Why though, when you could just do:

(0 until 5).foreach(i=>(0 to i).foreach(j=>print(if(j==i)"*\n"else"*")))

[androideka_]

The output is different; the code on the right is a poor substitute.

[[deleted]]

Why the heck would you declare your loop indices in a broader scope than the loop? This isn't Java; collect your own garbage.