Putting a word in alphabetical order.

I'm trying to put a word into alphabetical order (i.e. so that the letters contained within are in alphabetical order), but do you have any idea how I would do this with a word of unknown length?
I can think how to do it with one character and the character next to it using a for loop, but not so it checks the other letters in the sequence against it.

If you have any ways about how to do this then I would appreciate it.

For example I'm trying to write it so that:
ball would become abll, but also so that program would become agmoprr, and so on and so forth for any length word.

bubble sort/quick sort/select sort. <<-- use google and search for the code. Quick sort is available already via stdlib.h, but I don't think you should use that for your class.

Wikipedia's list of sorting algorithms: http://en.wikipedia.org/wiki/Sorting_algorithm

Here are some of the simpler ones:

http://en.wikipedia.org/wiki/Bubble_sort
http://en.wikipedia.org/wiki/Cocktail_sort
http://en.wikipedia.org/wiki/Insertion_sort
http://en.wikipedia.org/wiki/Selection_sort

Code:

---

for(i=0;i<strlen(str)-2;i++)
    {
        for(j=i+1;j<strlen(str)-1;j++)
        {
            if(str[i] > str[j])
            {
                temp = str[i];
                str[i] = str[j];
                str[j] = temp;
            }
        }
    }

---

this code is just to start you up

ssharish2005

Uh huh . . . besides the fact that this is very likely homework, you're calling strlen() to calculate the length of the string for every iteration of the loop, which is very expensive in CPU time. Save the result.

Code:

---

size_t len = strlen(str);

---

DWKS u are right, has kills the CPU time. :)

Thanks

ssharish2005

Yeah he introduced Bubble Sort to us today (well he actually described what it is, and we had to implement it), so I reckon that that is the right way to attack this problem. Thanks for your help guys.

Right so I've made the swap thing into a function and my code is as follows:

Code:

---

char swap2(char word2, int length)
{
    char temp[1];
    int i;
    int j;

    for(i=0; i<(length-2);i++)
    {
              for(j=i+1; j<(length-1); j++)
              {
                        if(word2[i] > word2[j])
                        {
                            temp=word2[i];
                            word2[i]=word2[j];
                            word2[j]=temp;
                          }
                }
      }
}

---

But it won't compile. Any ideas why? I have a feeling I need to use strcpy, for swapping the characters around, but its not picking up the individual characters (I don't think). Any pointers?

shouldn't word2 be a char* ?

Also, you've made your function return a char, but you don't return anything. Make the function void or return 0; or something.

and seems to be that
char temp[1];

should be
char temp;
from how do you use it

Quote:

---

But it won't compile

---

If u copy and paste it, that would be the result u will get. Study the logic and then code

ssharish2005

Quote:

---

Originally Posted by ssharish2005

Code:

---

for(i=0;i<strlen(str)-2;i++)
    {
        for(j=i+1;j<strlen(str)-1;j++)
        {
            if(str[i] > str[j])
            {
                temp = str[i];
                str[i] = str[j];
                str[j] = temp;
            }
        }
    }

---

this code is just to start you up

ssharish2005

---

That's kind of misleading. Look at this, from http://en.wikipedia.org/wiki/Bubble_sort:

Code:

---

function bubble_sort(list L, number listsize)
    loop
        has_swapped := 0 //reset flag
        for number i from 1 to (listsize - 1)
            if L[i] > L[i + 1] //if they are in the wrong order
                swap(L[i], L[i + 1]) //exchange them
                has_swapped := 1 //we have swapped at least once, list may not be sorted yet
            endif
        endfor
        //if no swaps were made during this pass, the list has been sorted
        if has_swapped = 0
            exit
        endif
    endloop
endfunction

---

And see, the OP's copied it . . .

Code:

---

if(word2[i] > word2[j])

---

Perhaps it may work as you have it, but even so it doesn't use the Bubble Sort algorithm.

[edit] Remember, if you access a variable like so

Code:

---

variable[x]

---

it must be an array (or a pointer). [/edit]