From 46564e2b4ac5e53d026650a5b6a6bc7a334ab5f7 Mon Sep 17 00:00:00 2001
From: HetalSharma <75665601+HetalSharma@users.noreply.github.com>
Date: Sun, 10 Oct 2021 12:41:03 +0530
Subject: [PATCH] Create shell sort.cpp

---
 .../Searching and Sorting/shell sort.cpp      | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 Data Structures/Searching and Sorting/shell sort.cpp

diff --git a/Data Structures/Searching and Sorting/shell sort.cpp b/Data Structures/Searching and Sorting/shell sort.cpp
new file mode 100644
index 00000000..15913d14
--- /dev/null
+++ b/Data Structures/Searching and Sorting/shell sort.cpp	
@@ -0,0 +1,54 @@
+// C++ implementation of Shell Sort
+#include <iostream>
+using namespace std;
+
+/* function to sort arr using shellSort */
+int shellSort(int arr[], int n)
+{
+	// Start with a big gap, then reduce the gap
+	for (int gap = n/2; gap > 0; gap /= 2)
+	{
+		// Do a gapped insertion sort for this gap size.
+		// The first gap elements a[0..gap-1] are already in gapped order
+		// keep adding one more element until the entire array is
+		// gap sorted
+		for (int i = gap; i < n; i += 1)
+		{
+			// add a[i] to the elements that have been gap sorted
+			// save a[i] in temp and make a hole at position i
+			int temp = arr[i];
+
+			// shift earlier gap-sorted elements up until the correct
+			// location for a[i] is found
+			int j;		
+			for (j = i; j >= gap && arr[j - gap] > temp; j -= gap)
+				arr[j] = arr[j - gap];
+			
+			// put temp (the original a[i]) in its correct location
+			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;
+}