Simple Shell Sort Program using functions in C++

About this program

This is an example program in sorting programs. Read the concept first: Understanding Array in C++, then study the code and output below.

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 C++ Programs,C++ Functions and Array Examples */

#include <iostream>
#include<conio.h>
#include<stdlib.h>

#define MAX_SIZE 5

using namespace std;

void shell_sort(int[]);

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

    cout << "Simple C++ Shell Sort Example - Functions and Array\n";
    cout << "\nEnter " << MAX_SIZE << " Elements for Sorting : " << endl;
    for (i = 0; i < MAX_SIZE; i++)
        cin >> arr_sort[i];

    cout << "\nYour Data   :";
    for (i = 0; i < MAX_SIZE; i++) {
        cout << "\t" << 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;
                }
            }

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

    }

    cout << "\n\nSorted Data :";
    for (i = 0; i < MAX_SIZE; i++) {
        cout << "\t" << 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)

Press any key to continue . . .

Related Pages

Learn the concept first, then study the code:

• Data Structures — Browse all Data Structures.
• Understanding Array in C++ — Tutorial — arrays underpin sorting algorithms.
• Simple Bubble Sort Program in C++ — More in sorting programs.
• Simple Bubble Sort Program using functions in C++ — More in sorting programs.