Create shellsort

Sorting/shellsort

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+// C++ implementation of Shell Sort
+#include <iostream>
+using namespace std;
+
+
+int shellSort(int arr[], int n)
+{
+	// Start with a big gap, then reduce the gap
+	for (int gap = n/2; gap > 0; gap /= 2)
+	{
+		for (int i = gap; i < n; i += 1)
+		{
+			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;
+}
+
+void printArray(int arr[], int n)
+{
+	for (int i=0; i<n; i++)
+		cout << arr[i] << " ";
+}
+
+int main()
+{
+	int arr[] = {12, 34, 54, 2, 3}, i;
+	int n = sizeof(arr)/sizeof(arr[0]);
+
+	cout << "Array before sorting: \n";
+	printArray(arr, n);
+
+	shellSort(arr, n);
+
+	cout << "\nArray after sorting: \n";
+	printArray(arr, n);
+
+	return 0;
+}