I'v waisted 2 hours of my life.

[dynamicVoidMain]

Thats right.

2 miserable hours trying to make a decent sorting algorithm in Java. I don't know, but I tried 3 times, and each time I gave up in the mess of for loops nested in each other.


Could anyone help me by sharing some ideas/code or something for sorting arrays in alphabetical order java?

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Last edited by dynamicVoidMain; October 12th, 2006 at 14:50..

[Coolsvilleman]

what do you mean alphabetical order, are there strings or characters in the array? BTW java has some builtin sorting functions.

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[Proto]

uhh... well normally I'm against making other people homeworks, but you might want to take a look at some easy sorting algorithms like Bubblesort, Insertion sort or others.

[dynamicVoidMain]

Originally Posted by Coolsvilleman

what do you mean alphabetical order, are there strings or characters in the array? BTW java has some builtin sorting functions.

Strings. I know, its in java.util.Array, but I'd rather not use that.

Originally Posted by Proto

uhh... well normally I'm against making other people homeworks, but you might want to take a look at some easy sorting algorithms like Bubblesort, Insertion sort or others.

While I do learn java at uni this isn't homework

[Proto]

Well in that case what I'd do is creating a little function that can compare two strings to see which ones goes first, and then just using that with one of the sorting algorithms that I mentioned

[Shin_Gouki]

sorting?
dunno u could try something with getting the ASCI code of each letter and try to sort using that (to apply bubble or soemhting else on that should be easy)
i hope i got u right
BTW:
2 h wasted LOL
if u just started with programming...well here some news for u:
programming takes time
what do u think why e.g. PCSX2 took 6 years to its current status?
Because the devs were lazy and did not work 24h a days 7 days a week..
no i think not , i guess "because programming needs" some time
And if ur not an "Einstein" then it will take even more then 2 h agan to get it workin.
BUT the experience u get IF u get it working SHOULD be worth it.
(i guess)
Einstein said, and IMO hes right:
Experince is knowledge, everything else is just information (from gnemu startside)
So good luck!
just paste some code in here, or try the google search code
we might help u
wbr Shin Gouki

[dynamicVoidMain]

Originally Posted by Proto

uhh... well normally I'm against making other people homeworks, but you might want to take a look at some easy sorting algorithms like Bubblesort, Insertion sort or others.

Originally Posted by Proto

Well in that case what I'd do is creating a little function that can compare two strings to see which ones goes first, and then just using that with one of the sorting algorithms that I mentioned

yeah thats the idea, but it really isn't working. Silly code

I'm getting a lot of experience doing it though, so its a win-win situation. I just hope I do get it to work eventually because I know it'll make me really happy (feeling of pety accomplishment no doubt :P)




edit: Ok, so I dropped the project for a little while, I just got back on it. All I did was change the position of where I was incrementing some variables, I also deleted one variable assigment at a certain point in the flow, and BAM! It worked I didn't get it to work in one go, took some tweaking here and there, I found messing with something gave me far more pleasing results, with some more messing of it I eventually got what I wanted.


I knew the algorithm I had in mind would work, and I knew the code I had should have been working, and it did, I just removed one variable assimgent and changed where another variable was being incremented and it worked

Oh wow, I feel so proud (in a crappy, I'm so useless a n00b programmer sort of way )

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Last edited by dynamicVoidMain; October 12th, 2006 at 23:18..

[ChankastRules]

Few things is as satisfying for a programmer as getting an idea to work! Congratz!

[GaveUpTomorrow]

I wouldn't say that you wasted two hours, but more like you learned ways not to solve the problem for two hours That's the way I look at it when scripting in Ruby, ...if I spend two hours trying to get something to work and it doesn't, I know from then on not to try those methods anymore and find a better way

[dynamicVoidMain]

yeah suppose so.. but still...


gah, I'm just glad it worked really, I mean when it did I was like 'holy crap! that came out of no where!', I hadn't canged the code much, just a little tweak here and there, then suddenly its sorting everything out!

[Chrono Archangel]

what sort of sorting algorithm you've ended up using? I've looked through some old java stuff i did for school and here are a few ways we had to do :
(sorry for the french names and all... and i don't gauranty the accuracy of this code since its old, and i dont feel like going through it )

	public static void trier( int table[] ) {
		int nbElements = table.length;
		int temp=0;
		int j;
		for (int k=1;k<nbElements;k++){
			temp = table[k];
			j = k-1;
			while (j>=0 && temp < table[j]) {
				table[j+1] = table[j];
				if (j==0){
					table[j]=temp;
				}
				j--;
			} 
			table[j+1] = temp;
		}
	}

	public static void trier( int table[] ) {
		int nbElements = table.length;
		int tableCompteur[] = new int[nbElements];
		int tableTrier[] = new int[nbElements];
		int indice=0;
		
		for (int k=0;k<nbElements;k++){
			tableCompteur[k] = 0;
			tableTrier[k] = 0;
		}
		
		for (int k=0;k<nbElements;k++){
			for (int j=k; j<nbElements;j++){
				if (table[k]>=table[j]){
					tableCompteur[k]+=1;
				}else{
					tableCompteur[j]+=1;
					}
			}
		}
		for (int k=0;k<nbElements;k++){
			indice = tableCompteur[k];
			tableTrier[indice] = table[k];
		}
		
		for (int k=0;k<nbElements;k++){
			table[k] = tableTrier[k];
		}
		
			
	}

	public static void trier( int table[] ) {
		int nbSwitch = 0;
		int temp;
		int fin = table.length;
		
		do {
			nbSwitch = 0;
			for (int k=0;k<fin-1;k++){
				if (table[k+1]<table[k]){
					temp=table[k];
					table[k]=table[k+1];
					table[k+1]=temp;
					nbSwitch+=1;
				}
				
			}
			fin-=1;
		} while (fin!=1&&nbSwitch!=0);
	}

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[Kurbster]

All 3 of those are only able to sort integers. Unfortunately for strings, it's not that easy

The only other thing I can think of is converting the first letter into a hexadecimal value and comparing that.

Or just use the method in java.util.Array, sheesh

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[ChankastRules]

Quicksort works fine for strings too, just as long as you know what one string is bigger than the other means. ( This could be length... or first letter, or the total ASCII numbers combined or whatever )

[Chrono Archangel]

Originally Posted by Kirby

All 3 of those are only able to sort integers. Unfortunately for strings, it's not that easy

The only other thing I can think of is converting the first letter into a hexadecimal value and comparing that.

Or just use the method in java.util.Array, sheesh

of course, our assignments were for integers only we were still newbies at that time

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[dynamicVoidMain]

Yeah, sorting integers is alot easier than strings. With a string you use a.compareTo(b) whcih returns a negative value if a is less than be and a positive one if its the opposite. I thought I could make it work, but didn't turn otu that way.


Basically what I did was startw ith the first word, and work my way down the list comparing, ifcompareTo returned a negative value I exchanged their positions and went back to the top of the list. I know this is sa real algorithm with a real name, but the name escapes me

[Chrono Archangel]

recursive functions come to think of it, i do beleive we made one using the .compare

id have to look through my folders

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[dynamicVoidMain]

Originally Posted by Kirby

All 3 of those are only able to sort integers. Unfortunately for strings, it's not that easy

The only other thing I can think of is converting the first letter into a hexadecimal value and comparing that.

Or just use the method in java.util.Array, sheesh

while I can use arrays/vectors I'd rather practice with linked lists as my end of year exam will probably be asking I create one, besides, arrays aren't dynamic data structures so they can't do everything linked lists can

[Proto]

Hmm... you can create arrays with dynamic sizes, albeit you can't change their size once they are created if that's what you refer to.

C:
int myArraySize = ||| some number you get elsewhere |||;
char* myArray = malloc(sizeof(char) * myArraySize);

or int[] arr = new int[someNumber]; in java or c++

Indeed with Linked Lists and the like you can attach a new element as many times as you want, however because of the secuential nature of these data structures it makes them unpractical for large data sizes... it all depends on your needs I guess...

[dynamicVoidMain]

yeah, and the type of questions they'll be asking on the exam

I do need to change it on the fly, I could use vectors except the lecturer made it clear such questions wouldn't be on the exam, if it was going to be about a linked list, it would be about making them.



Anyway, right now I'm busting caps trying to work out virtual functions in C++ , atleast its slightly easier now cos the problem is rpetty much out of a text book