Added Cocktail Sort implementation in C++ (thuva4#536)

Akshama · thuva4 · commit 9d8ba083e6aa · 2017-11-07T16:00:59.000+05:30
* Create cocktail_sort.cpp

* Update cocktail_sort.cpp

* Rename Cocktail_Sort/Cpp/cocktail_sort.cpp to CocktailSort/Cpp/CocktailSort.cpp
diff --git a/CocktailSort/Cpp/CocktailSort.cpp b/CocktailSort/Cpp/CocktailSort.cpp
@@ -0,0 +1,76 @@
+//Author: Akshama
+#include<bits/stdc++.h>
+using namespace std;
+ 
+// Sorts array a[0..n-1] using Cocktail sort
+void CocktailSort(int a[], int n)
+{
+    bool swapped = true;
+    int start = 0;
+    int end = n-1;
+ 
+    while (swapped)
+    {
+        // reset the swapped flag on entering
+        // the loop, because it might be true from
+        // a previous iteration.
+        swapped = false;
+ 
+        // loop from left to right same as
+        // the bubble sort
+        for (int i = start; i < end; ++i)
+        {
+            if (a[i] > a[i + 1])
+            {
+                swap(a[i], a[i+1]);
+                swapped = true;
+            }
+        }
+ 
+        // if nothing moved, then array is sorted.
+        if (!swapped)
+            break;
+ 
+        // otherwise, reset the swapped flag so that it
+        // can be used in the next stage
+        swapped = false;
+ 
+        // move the end point back by one, because
+        //  item at the end is in its rightful spot
+        --end;
+ 
+        // from right to left, doing the
+        // same comparison as in the previous stage
+        for (int i = end - 1; i >= start; --i)
+        {
+            if (a[i] > a[i + 1])
+            {
+                swap(a[i], a[i+1]);
+                swapped = true;
+            }
+        }
+ 
+        // increase the starting point, because
+        // the last stage would have moved the next
+        // smallest number to its rightful spot.
+        ++start;
+    }
+}
+ 
+/* Prints the array */
+void printArray(int a[], int n)
+{
+    for (int i=0; i<n; i++)
+        printf("%d ", a[i]);
+    printf("\n");
+}
+ 
+int main()
+{
+    int arr[] = {5, 1, 4, 2, 8, 0, 2};
+    int n = sizeof(arr)/ sizeof(arr[0]);
+    CocktailSort(arr,n);
+    printf("Sorted array :\n");
+    printArray(arr,n);
+    return 0;
+}
