Merge pull request #2480 from panda311/master

Added Circle Sort in C++

sort/circle_sort/C++/circle_sort.cpp

@@ -0,0 +1,70 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+// Function to perform circular swaps recursively
+// Returns true if there was a swap
+// operation performed.
+bool circleSortRec(int a[], int low, int high)
+{
+  bool swapped = false;
+
+  // base case
+  if (low == high)
+    return false;
+
+  int lo = low, hi = high;
+
+  while (lo < hi)
+  {
+    // swaps the pair of elements if true
+    if (a[lo] > a[hi])
+    {
+      swap(a[lo], a[hi]);
+      swapped = true;
+    }
+    lo++;
+    hi--;
+  }
+
+  // special case arises only for list of odd size
+  if (lo == hi)
+    if (a[lo] > a[hi + 1])
+    {
+      swap(a[low], a[hi + 1]);
+      swapped = true;
+    }
+
+  // recursive case to check the traverse lists as sub lists
+  int mid = (high - low) / 2;
+  bool firstHalf = circleSortRec(a, low, low + mid);
+  bool secondHalf = circleSortRec(a, low + mid + 1, high);
+
+  return swapped || firstHalf || secondHalf;
+}
+
+void circleSort(int a[], int n)
+{
+  // Keep calling circleSortRec while there is a swap operation.
+  while (circleSortRec(a, 0, n - 1))
+  {
+    ;
+  }
+}
+
+int main()
+{
+  int a[] = {7, 5, 3, 1, 2, 4, 6, 8};
+  int n = sizeof(a) / sizeof(a[0]);
+
+  printf("\nUnsorted : ");
+  for (int i = 0; i < n; i++)
+    cout << a[i] << " ";
+
+  circleSort(a, n);
+
+  printf("\nSorted : ");
+  for (int i = 0; i < n; i++)
+    cout << a[i] << " ";
+
+  return 0;
+}