Ordering items in an array

[CodeRazor]

My array is

int[] list = new int[3]{20,99,6};

Using a for-loop, how can I order the output of this array. I don't want to
use a sorted list.

I know this is straightforward but can't figure it out.

thank you!

[Adam Barker]

Re: Ordering items in an array

int[] i = new int[5] { 10, 9, 15, 2, 8 };

Array.Sort(i);

"CodeRazor" <CodeRazor@disc ussions.microso ft.com> wrote in message
news:50077FB1-577F-49D9-81F6-74B42E2B123A@mi crosoft.com...[color=blue]
> My array is
>
> int[] list = new int[3]{20,99,6};
>
> Using a for-loop, how can I order the output of this array. I don't want
> to
> use a sorted list.
>
> I know this is straightforward but can't figure it out.
>
> thank you![/color]

[Marinus Holkema]

Re: Ordering items in an array

But if you realy, realy need a for-loop:

int[] list = new int[5]{12,1,105,99,66 };
int length = list.GetLength( 0)-1;
for (int i=0;i<length;)
{
if (list[i] > list[i+1])
{
int a=list[i+1];
list[i+1]=list[i];
list[i]=a;
if (i>0)
i--;
}
else
i++;

}







"Adam Barker" wrote:
[color=blue]
> int[] i = new int[5] { 10, 9, 15, 2, 8 };
>
> Array.Sort(i);
>
> "CodeRazor" <CodeRazor@disc ussions.microso ft.com> wrote in message
> news:50077FB1-577F-49D9-81F6-74B42E2B123A@mi crosoft.com...[color=green]
> > My array is
> >
> > int[] list = new int[3]{20,99,6};
> >
> > Using a for-loop, how can I order the output of this array. I don't want
> > to
> > use a sorted list.
> >
> > I know this is straightforward but can't figure it out.
> >
> > thank you![/color]
>
>
>[/color]

[CodeRazor]

Re: Ordering items in an array

Thaks Adam

[Adam Barker]

Re: Ordering items in an array

Despite looking awful, this method is actually far far quicker than
Array.Sort() !

"Marinus Holkema" <MarinusHolkema @discussions.mi crosoft.com> wrote in
message news:55984DB2-12AA-492D-99CE-4A1C1695120C@mi crosoft.com...[color=blue]
> But if you realy, realy need a for-loop:
>
> int[] list = new int[5]{12,1,105,99,66 };
> int length = list.GetLength( 0)-1;
> for (int i=0;i<length;)
> {
> if (list[i] > list[i+1])
> {
> int a=list[i+1];
> list[i+1]=list[i];
> list[i]=a;
> if (i>0)
> i--;
> }
> else
> i++;
>
> }
>
>
>
>
>
>
>
> "Adam Barker" wrote:
>[color=green]
>> int[] i = new int[5] { 10, 9, 15, 2, 8 };
>>
>> Array.Sort(i);
>>
>> "CodeRazor" <CodeRazor@disc ussions.microso ft.com> wrote in message
>> news:50077FB1-577F-49D9-81F6-74B42E2B123A@mi crosoft.com...[color=darkred]
>> > My array is
>> >
>> > int[] list = new int[3]{20,99,6};
>> >
>> > Using a for-loop, how can I order the output of this array. I don't
>> > want
>> > to
>> > use a sorted list.
>> >
>> > I know this is straightforward but can't figure it out.
>> >
>> > thank you![/color]
>>
>>
>>[/color][/color]

[Jon Skeet [C# MVP]]

Re: Ordering items in an array

Adam Barker <adam@NO_SP_A M> wrote:[color=blue]
> Despite looking awful, this method is actually far far quicker than
> Array.Sort() ![/color]

While it may be quicker to do a bubble sort for a few items, it gets
*much* slower over larger arrays.

Try the following program with different sizes. On my box, an array
with 100,000 elements took 0.06s to sort with Array.Sort, and 13.8s to
sort with the bubble sort. Of course, the time taken will depend on the
actual data (a bubble sort is very quick on data which is already
sorted).

using System;

class Test
{
static void Main(string[] args)
{
int size = int.Parse(args[0]);

int[] testData = new int[size];
Random rng = new Random();
for (int i=0; i < size; i++)
{
testData[i] = rng.Next(size);
}

int[] testData2 = (int[]) testData.Clone( );

DateTime start = DateTime.Now;
Array.Sort(test Data);
DateTime end = DateTime.Now;
Console.WriteLi ne ("Array.Sort : {0}", end-start);

start = DateTime.Now;
BubbleSort(test Data2);
end = DateTime.Now;
Console.WriteLi ne ("BubbleSort : {0}", end-start);
}

static void BubbleSort (int[] array)
{
int length = array.GetLength (0)-1;
for (int i=0;i<length;)
{
if (array[i] > array[i+1])
{
int a=array[i+1];
array[i+1]=array[i];
array[i]=a;
if (i>0)
i--;
}
else
i++;

}
}
}


--
Jon Skeet - <skeet@pobox.co m>

http://www.pobox.com/~skeet

If replying to the group, please do not mail me too

[Daniel Jin]

Re: Ordering items in an array

it's really not. bubble sort has a running time of O(n^2). while
Array.Sort() uses quick sort which has the same worst time scenario, but
typically you can expect an average of n * log n, which works great on large
list as Jon has demonstrated.

"Adam Barker" wrote:
[color=blue]
> Despite looking awful, this method is actually far far quicker than
> Array.Sort() !
>
> "Marinus Holkema" <MarinusHolkema @discussions.mi crosoft.com> wrote in
> message news:55984DB2-12AA-492D-99CE-4A1C1695120C@mi crosoft.com...[color=green]
> > But if you realy, realy need a for-loop:
> >
> > int[] list = new int[5]{12,1,105,99,66 };
> > int length = list.GetLength( 0)-1;
> > for (int i=0;i<length;)
> > {
> > if (list[i] > list[i+1])
> > {
> > int a=list[i+1];
> > list[i+1]=list[i];
> > list[i]=a;
> > if (i>0)
> > i--;
> > }
> > else
> > i++;
> >
> > }
> >
> >
> >
> >
> >
> >
> >
> > "Adam Barker" wrote:
> >[color=darkred]
> >> int[] i = new int[5] { 10, 9, 15, 2, 8 };
> >>
> >> Array.Sort(i);
> >>
> >> "CodeRazor" <CodeRazor@disc ussions.microso ft.com> wrote in message
> >> news:50077FB1-577F-49D9-81F6-74B42E2B123A@mi crosoft.com...
> >> > My array is
> >> >
> >> > int[] list = new int[3]{20,99,6};
> >> >
> >> > Using a for-loop, how can I order the output of this array. I don't
> >> > want
> >> > to
> >> > use a sorted list.
> >> >
> >> > I know this is straightforward but can't figure it out.
> >> >
> >> > thank you!
> >>
> >>
> >>[/color][/color]
>
>
>[/color]