Sorting 2Darrays in java

[peeweegary]

Hey all.
Is it possible to sort letters a-z, A-Z that have been stored in a String array or do the letters have to be converted to ascii first?

The array has a total of 54 spaces each filled with a letter.

This is all for a school assignment but the general coding for this was never in the class notes.

Thanks in advance

 

[Sharky.]

You should be able to run a straight compareTo(), as a < z < A < Z in Java anyway. No need to convert to ASCII.

If you'd like I can post up how I was taught to do it [for loop + compareTo(charAt(x))].

 

[peeweegary]

oooo yes please...Im only taking grade 11 computer science so i dont know much of java yet. Barely scratching the surface of java.

 

[Sharky.]

Oops, sorry for forgetting about this thread

Using bubble sort (really bad idea, I know... lol)

public void sort(String[] array){
   int pass = 1;
   boolean swaps = false;
  do {
     swaps = false; //nothing has been swapped yet
     //compare each adjacent element
    for(int i = 0; i < array.length - pass; i++) {
        if(array[i].compareTo(array[i+1]) > 0) {
          //swap pair of characters
          String temp = array[i];
          array[i] = array[i+1];
          array[i+1] = temp;
          swaps = true;
         } //closing if
     } //closing for
     pass++;
  } while (swaps); //closing do, string array is now sorted
} //closing method

Of course, you can cheat by calling Arrays.sort(stringArray) if you import java.util.Arrays!

 

[peeweegary]

thanks sharky =)

EDIT: How would this work if the array was 2D?

 

[Sharky.]

You mean 3D? Is it even possible to sort a 3D array?

edit: ah, I'm confusing myself. I'd imagine you could run the sort on both directions of the array - bubble the "largest" character in each "row" of the array to the end and bubble the largest in each "column" down to the bottom. When I first read the thread I though you were referring to normal arrays.

 

[ferrari_chris]

How would you sort a 2-dimensional array? You could sort each sub array, but would prioritise one array over another?

 

[Sharky.]

I had an idea where you convert the 2D array to a 1D array: basically stitch each row to the end of the previous, then sort the resultant 1D array, then "redimensionify" - put back into a 2D array.

Voila! Sorted, and 2D.

 

[peeweegary]

^^thats what i said to my friend but apparently in the rubric, to obtained a level 4 we have to sort the input in a 2D array....

What you said would've just gotten me a level 3 -_-'...I hate this

Oh well i'll what what you said Sharky...its better than having nothing.

Thanks fellas 👍