Simple Shell Sort Program using functions 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 C Program example using functions

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

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

#define MAX_SIZE 5

void shell_sort(int[]);

int main() {
  int arr_sort[MAX_SIZE], i;

  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]);
  }

  shell_sort(arr_sort);
  getch();

}

void shell_sort(int fn_arr[]) {
  int i, j, k, a, t;

  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 (fn_arr[k + i] >= fn_arr[k])
          break;
        else {
          //Swapping Values 
          t = fn_arr[k];
          fn_arr[k] = fn_arr[k + i];
          fn_arr[k + i] = t;
        }
      }

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

  }

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

Sample Output:

Simple Shell Sort Example - Functions and Array

Enter 5 Elements for Sorting
56
45
90
18
7

Your Data   :   56      45      90      18      7
Shell Sort Iteration [2:2]      56      45      90      18      7
Shell Sort Iteration [2:3]      56      18      90      45      7
Shell Sort Iteration [2:4]      7       18      56      45      90
Shell Sort Iteration [1:1]      7       18      56      45      90
Shell Sort Iteration [1:2]      7       18      56      45      90
Shell Sort Iteration [1:3]      7       18      45      56      90
Shell Sort Iteration [1:4]      7       18      45      56      90

Sorted Data :   7       18      45      56      90

------------------
(program exited with code: 0)

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