Selection Sort in C

/*

 * Input  : A sequence of n numbers <a1, a2, ..., an>

 * Output : Sorted list <a1', a2', ..., an'>

 *          of the input sequence in ascending order

 * Method : Find the minimum value in the list and swap

 *          it with the first position. Repeat the same for

 *          the remainder of the list, starting with the second

 *          position and advancing each time.

 */

#include<stdio.h>

#include<stdlib.h>

main()

{

  // Function declaration

  void selection_sort(int *, int);

  int *array = NULL; // Pointer to int, initialize to nothing.

  int n, i;

  printf("Enter number of elements: ");

  scanf("%d", &n);

  // Dynamically allocate memory for n elements

  array = (int *)calloc(n, sizeof(int));

  // Reading the elements

  printf("\nEnter the elements:");

  for (i = 0;i < n;i++)

    scanf("%d", &array[i]);

  // Invoke selection_sort

  selection_sort(array, n);

  // Display sorted array

  printf("sorted array:");

  for (i = 0;i < n;i++)

    printf("%d ", array[i]);

  printf("\n");

}

selection_sort(int *arr, int num)

{

  int i, j, small, pos, temp;

  for (i = 0;i < num;i++) {

    small = arr[i];

    pos = i;

    for (j = i;j < num;j++) {

      if (arr[j] < small) {

        small = arr[j];

        pos = j;

      }

    }

    temp = arr[i];

    arr[i] = small;

    arr[pos] = temp;

  }

}


Code can be downloaded @ GitHub:selection_sort.c

Written by Munia Balayil