ShellSort.cpp

#include  <iostream>
using namespace std;

// shell sort implementation
int shellSort(int arr[], int N)
{
    for (int gap = N/2; gap > 0; gap /= 2)
       {
    for (int i = gap; i < N; i += 1)
       {
            //sort sub lists created by applying gap
int temp = arr[i];

int j;
for (j = i; j >= gap && arr[j - gap] > temp; j -= gap)
arr[j] = arr[j - gap];

arr[j] = temp;
        }
    }
    return 0;
}

int main()
{
    int arr[] = {45,23,53,43,18,24,8,95,101}, i;
    //Calculate size of array
    int N = sizeof(arr)/sizeof(arr[0]);

    cout << "Array to be sorted: \n";
    for (int i=0; i<N; i++)
        cout << arr[i] << " ";

    shellSort(arr, N);

    cout << "\nArray after shell sort: \n";
    for (int i=0; i<N; i++)
        cout << arr[i] << " ";

    return 0;
}