Sort Algorithm Part-1 Selection Sort

Sort Algorithm

Part -1

Selection Sort

 

 

Table of Contents

Table of Contents. 2

1. Definition. 3

2. Implements in ANSI C. 3

2.1 List of c files. 3

2.2 Source code. 3

2.2.1 main.c 3

2.2.2 def.h. 3

2.2.3 sort.h. 3

2.2.4 sort.c 3

3. Implements in C#. 4

3.1 List of C# files. 4

3.2 Source code. 4

3.2.1 Main.cs. 4

3.2.2 Sorter.cs. 4

 

1. Definition

A sorting technique that is typically used for sequencing small lists. It starts by comparing the entire list for the lowest item and moves it to the #1 position. It then compares the rest of the list for the next-lowest item and places it in the #2 position and so on until all items are in the required order. Selection sorts perform numerous comparisons, but fewer data movements than other methods.

 

2. Implements in ANSI C

2.1 List of c files

1. main.c
2. def.h
3. sort.h
4. sort.c

2.2 Source code

2.2.1 main.c

#include <stdio.h>

#include <string.h>

#include "sort.h"

 

int main(int argc, char **argv) {

    Item itm[] = {"ASORTINGEXAMPLE"};

    s_sort(itm, 0, strlen(itm));

 

    return 0;

}

2.2.2 def.h

typedef char Item, *PItem;

 

#define less(a, b)  ((a) < (b))

#define exch(a, b)  {Item tmp; tmp = (a); (a) = (b); (b) = tmp;}

 

2.2.3 sort.h

#include "def.h"

 

void s_sort(Item*, int, int);

 

2.2.4 sort.c

#include "sort.h"

 

void s_sort(Item*, int, int);

 

void s_sort(Item item[], int l, int r) {

    int i;

 

    for (i = l; i < r - 1; i++) {

        int min = i, j;

 

        for (j = i + 1; j < r; j++) {

            if (less(item[j], item[min]))

                min = j;

        }

       

        exch(item[i], item[min]);

    }

}

 

 

3. Implements in C#

3.1 List of C# files

1. Main.cs
2. Sorter.cs

3.2 Source code

3.2.1 Main.cs

using System;

using System.Collections;

 

namespace AlgorithmPractice {

    /// <summary>

    /// Summary description for TestClass.

    /// </summary>

    class TestClass {

        /// <summary>

        /// The main entry point for the application.

        /// </summary>

        [STAThread]

        static void Main (string[] args) {

            char[] charItem = {'A', 'S', 'O', 'R', 'T',

                                  'I', 'N', 'G', 'E', 'X',

                                  'A', 'M', 'P', 'L', 'E'};

 

            int[] intItem = new int[]{1, 5, 3, 6, 10,

                                         55, 9, 2, 87, 12,

                                         34, 75, 33, 47, 1};

 

            Sorter.SelectionSort(charItem, null, 0, charItem.Length);

            Sorter.SelectionSort(intItem, null, 0, intItem.Length);

 

            System.Diagnostics.Debug.WriteLine(new string(charItem));

        }

    }

}

 

3.2.2 Sorter.cs

using System;

using System.Collections;

 

namespace AlgorithmPractice

{

      /// <summary>

      /// Summary description for Sorter.

      /// </summary>

      public class Sorter

      {

            private Sorter(){}

 

        public static void SelectionSort(

            IList item, IComparer comparer,

            int l, int r) {

            if (null == comparer)

                comparer = Comparer.Default;

 

            for (int i = l; i < r - 1; i++) {

                int min = i;

                object tmp;

 

                for (int j = i + 1; j < r; j++)

                    if (comparer.Compare(item[j], item[min]) < 0)

                        min = j;

 

                tmp = item[i];

                item[i] = item[min];

                item[min] = tmp;

            }

        }

      }

}