cycleSort.cpp

added new cycle sort code in c++

C++/cycleSort.cpp

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+// C++ program to implement cycle sort 
+#include <iostream> 
+using namespace std; 
+
+// Function sort the array using Cycle sort 
+void cycleSort(int arr[], int n) 
+{ 
+	// count number of memory writes 
+	int writes = 0; 
+
+	// traverse array elements and put it to on 
+	// the right place 
+	for (int cycle_start = 0; cycle_start <= n - 2; cycle_start++) { 
+		// initialize item as starting point 
+		int item = arr[cycle_start]; 
+
+		// Find position where we put the item. We basically 
+		// count all smaller elements on right side of item. 
+		int pos = cycle_start; 
+		for (int i = cycle_start + 1; i < n; i++) 
+			if (arr[i] < item) 
+				pos++; 
+
+		// If item is already in correct position 
+		if (pos == cycle_start) 
+			continue; 
+
+		// ignore all duplicate elements 
+		while (item == arr[pos]) 
+			pos += 1; 
+
+		// put the item to it's right position 
+		if (pos != cycle_start) { 
+			swap(item, arr[pos]); 
+			writes++; 
+		} 
+
+		// Rotate rest of the cycle 
+		while (pos != cycle_start) { 
+			pos = cycle_start; 
+
+			// Find position where we put the element 
+			for (int i = cycle_start + 1; i < n; i++) 
+				if (arr[i] < item) 
+					pos += 1; 
+
+			// ignore all duplicate elements 
+			while (item == arr[pos]) 
+				pos += 1; 
+
+			// put the item to it's right position 
+			if (item != arr[pos]) { 
+				swap(item, arr[pos]); 
+				writes++; 
+			} 
+		} 
+	} 
+
+	// Number of memory writes or swaps 
+	// cout << writes << endl ; 
+} 
+
+// Driver program to test above function 
+int main() 
+{ 
+	int arr[] = { 1, 8, 3, 9, 10, 10, 2, 4 }; 
+	int n = sizeof(arr) / sizeof(arr[0]); 
+	cycleSort(arr, n); 
+
+	cout << "After sort : " << endl; 
+	for (int i = 0; i < n; i++) 
+		cout << arr[i] << " "; 
+	return 0; 
+}