Simple Shell Sort Program in C

Definition

Shellsort, also known as Shell sort or Shell's method, is an in-place comparison sort. It can be seen as either a generalization of sorting by exchange or sorting by insertion. The method starts by sorting pairs of elements far apart from each other, then progressively reducing the gap between elements to be compared.

Simple Shell Sort Program Example

/* Simple Shell Sort Program Using Array in C*/
/* Data Structure Programs,C Array Examples */

#include<stdio.h>
#include<conio.h>

#define MAX_SIZE 5

int main() {
  int arr_sort[MAX_SIZE], i, j, k, a, t;

  printf("Simple Shell Sort Example - Functions and Array\n");
  printf("\nEnter %d Elements for Sorting\n", MAX_SIZE);
  for (i = 0; i < MAX_SIZE; i++)
    scanf("%d", &arr_sort[i]);

  printf("\nYour Data   :");
  for (i = 0; i < MAX_SIZE; i++) {
    printf("\t%d", arr_sort[i]);
  }

  for (i = MAX_SIZE / 2; i > 0; i = i / 2) {
    for (j = i; j < MAX_SIZE; j++) {
      for (k = j - i; k >= 0; k = k - i) {
        if (arr_sort[k + i] >= arr_sort[k])
          break;
        else {
          //Swapping Values 
          t = arr_sort[k];
          arr_sort[k] = arr_sort[k + i];
          arr_sort[k + i] = t;
        }
      }

      printf("\nShell Sort Iteration [%d:%d] ", i, j);
      for (a = 0; a < MAX_SIZE; a++) {
        printf("\t%d", arr_sort[a]);
      }
    }

  }

  printf("\n\nSorted Data :");
  for (i = 0; i < MAX_SIZE; i++) {
    printf("\t%d", arr_sort[i]);
  }

  getch();
}

Sample Output:

Simple Shell Sort Example - Functions and Array

Enter 5 Elements for Sorting
4556
300
201
10
23

Your Data   :   4556    300     201     10      23
Shell Sort Iteration [2:2]      201     300     4556    10      23
Shell Sort Iteration [2:3]      201     10      4556    300     23
Shell Sort Iteration [2:4]      23      10      201     300     4556
Shell Sort Iteration [1:1]      10      23      201     300     4556
Shell Sort Iteration [1:2]      10      23      201     300     4556
Shell Sort Iteration [1:3]      10      23      201     300     4556
Shell Sort Iteration [1:4]      10      23      201     300     4556

Sorted Data :   10      23      201     300     4556