what's the fastest kind of sorting an array?

Question

I use selection sort, but I want a better sorting solution than this:

    static void SelectionSort(int[] a)
    {
        int temp, pmin;
        for (int i=0; i<a.Length-1; i++)
        {
            pmin=i;
            for (int j=i+1; j<a.Length; j++)
            if (a[j]<a[pmin])
                pmin=j;
            temp = a[i];
            a[i] = a[pmin];
            a[pmin] = temp;
        }
    }

possible duplicate of [C Array sorting tips](http://stackoverflow.com/questions/3893937/c-array-sorting-tips) — H H, Feb 11 '12 at 09:29

score 3 · Accepted Answer · answered Feb 11 '12 at 08:58

3

Just use:

Array.Sort(a);

Which will do a QuickSort.

answered Feb 11 '12 at 08:58

Marc Gravell

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score 2 · Answer 2 · answered Feb 11 '12 at 08:55

If you look on wikipedia, there is a good comparison of different sorting algorithms as far as their space and time complexity. Many are n lg n or n average time which should suit your needs nicely.

In addition, .NET comes with several sorting algorithms built in. Including Array.Sort() and List.Sort()

score 2 · Answer 3 · answered Feb 11 '12 at 08:57

2

use Array.Sort(a) or orderby in linq

answered Feb 11 '12 at 08:57

Chamika Sandamal

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score 1 · Answer 4 · answered Feb 11 '12 at 08:57

1

There is no absolute winner in sorting algorithms. The efficensy depends on size, content, state of the array. You only know what is best for you.

Look here for examples and measurement.

answered Feb 11 '12 at 08:57

Tigran

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score 1 · Answer 5 · answered Feb 11 '12 at 08:59

1

just use the built in function in Array: Array.Sort(a)

answered Feb 11 '12 at 08:59

John Woo

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score 0 · Answer 6 · answered Feb 11 '12 at 08:59

To have the fastest sorting algorithm you should use heap sort .It has the lowest time complexity compared to all other sorting algorithm

A program to implement Heap Sort

#include<stdio.h>

void restoreHup(int*,int);
void restoreHdown(int*,int,int);

void main()
{
    int a[20],n,i,j,k;
    printf("   Enter the number of elements to sort : ");
    scanf("%d",&n);

    printf("Enter the elements : ");
    for(i=1;i<=n;i++){
            scanf("%d",&a[i]);
            restoreHup(a,i);
    }


    j=n;
    for(i=1;i<=j;i++)
    {
            int temp;
            temp=a[1];
            a[1]=a[n];
            a[n]=temp;
            n--;
            restoreHdown(a,1,n);
    }

    n=j;

    printf("Here is it...");
    for(i=1;i<=n;i++)
            printf("%4d",a[i]);
    }



    void restoreHup(int *a,int i)
    {
     int v=a[i];

     while((i>1)&&(a[i/2]<v))
     {
            a[i]=a[i/2];
            i=i/2;
     }
     a[i]=v;
    }

    void restoreHdown(int *a,int i,int n)
   {
    int v=a[i];
    int j=i*2;
    while(j<=n)
    {
            if((j<n)&&(a[j]<a[j+1]))
                    j++;
            if(a[j]<a[j/2]) break;

            a[j/2]=a[j];
            j=j*2;
    }
    a[j/2]=v;
   }

what's the fastest kind of sorting an array?

6 Answers6