Update quickSort.h

quickSort.h

@@ -6,35 +6,27 @@ using namespace std;
 // -------------------------------------------------------------------------
 
 // Partition function
-int partition(vector <int> &v, int start, int end) {
+int partition(vector <int> &a, int start, int end) {
+
+	int pivot = a[end]; // Take the last element as a pivot 
+	int i = start - 1;
 
-	int pivot = start; // Take the first element as a pivot 
-	int i = start + 1;
-	int j = end;
 
-	while (i <= j) {
-
-		// If element at the left is bigger than the pivot and
-		// element at the right is smaller, swap elements
-
-		if (v[i] > v[pivot] && v[j] < v[pivot]) {
-			swap(v[i], v[j]);
-		}
-		else if (v[i] <= v[pivot]) { i++; } 
-		else if (v[j] >= v[pivot]) { j--; } 
+	for(int j=start;j<end;j++)
+	{
+		i++;
+		swap(a[i],a[j]);
 	}
-
-	// we swap the pivot into the right position
-	swap(v[j], v[pivot]);
-	return j;
+	swap(a[i+1],a[end]);
+	return i+1;
 }
 
 // QuickSort
 void quickSort(vector <int> &v, int start, int end) {
 
 	if (start < end) {
 		int pivot = partition(v, start, end);
-		quickSort(v, start, pivot);
+		quickSort(v, start, pivot-1);
 		quickSort(v, pivot + 1, end);
 	}
 }